1985 Jeep J20 Engine Oil

Your 1985 Jeep J20 might be the best vehicle youโ€™ve ever owned. Or you may just be struggling to keep it highway-approved. No matter the situation, Advance Auto Parts has the Engine Oil you desperately need.

We currently carry 51 Engine Oil to choose from for your 1985 Jeep J20, and our inventory prices range from as little as $6.49 up to $38.99.

On top of low prices, Advance Auto Parts offers 3 different trusted brands of Engine Oil for the 1985 Jeep J20. We only sell parts from trusted brands like Castrol so that you can find quality parts you can count on.

Donโ€™t take our word for it – check out customer ratings and reviews to buy with confidence. We have 6,729 reviews on our Engine Oil for the 1985 Jeep J20 from previous customers.

Have parts delivered straight to your home, or find the nearest Advance Auto Parts store to check out our Engine Oil stock in-person!

Engine Oil for Your 1985 Jeep J20

Castrol – EDGE High Mileage 5W-30 Advanced Full Synthetic Engine Oil: 5 Qt (Part No.15906E)

EDGE High Mileage 5W-30 Advanced Full Synthetic Engine Oil: 5 Qt

from

$38.99
Castrol EDGE High Mileage with Fluid TITANIUM Technology is the natural choice for drivers who demand maximum performance from their high mileage cars, which often operate at extreme temperatures. Castrol EDGE High Mileage provides up to 10X better high temperature performance than the latest industry standard to ensure optimal protection and oil flow over the drive cycle. As your car ages, it can lose performance and efficiency and is also more prone to catalytic converter failure. Castrol EDGE High Mileage is liquid engineered with Phosphorous Replacement Technology to reduce harmful phosphorus to protect the catalytic converter and preserve the life of your emission system. Castrol EDGE High Mileage helps your car defy its miles and extend maximum performance.

Product Features:
  • Patented phosphorus replacement technology to help extend the life of your emission system
  • 10x better high temperature performance (as measured in sequence iiih engine test vs. api sp test limit)
  • 6x better wear protection (as measured in latest sequence iva engine test)
  • 1.4x better sludge protection (as measured in sequence vh engine test vs. api sp test limit)
  • Maximum Performance: Castrol EDGE High Mileage with Fluid TITANIUM Technology is designed to provide maximum performance for high mileage cars, even in extreme temperatures.
  • Protects Catalytic Converter: Castrol EDGE High Mileage is liquid engineered with Phosphorous Replacement Technology to reduce harmful phosphorus, protecting the catalytic converter and preserving the life of your emission system.
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Castrol – GTX High Mileage 5W-30 Synthetic Blend Engine Oil: 5 Quart (Part No.15980E)

GTX High Mileage 5W-30 Synthetic Blend Engine Oil: 5 Quart

from

$30.99
Castrol GTX High Mileage motor oil is the leading consumer high-mileage brand. You won’t need to worry about using a high mileage oil or synthetic because this is both. It’s aย synthetic blend engine oilย that helps extend the life of your engine by protecting against sludge, wear and burn-off and also liquid engineered to protect your emission system. One of the leading causes of ‘check engine’ lights coming on in high mileage cars is actually catalytic converter failure, which can be caused by phosphorous in engine oil. While phosphorous is present in all engine oils for its ability to reduce wear, it is effectively poisonous to catalytic converters. Castrolย GTX High Mileage Motor Oil is liquid engineered with Phosphorous Replacement Technology to replace some of the phosphorous with an advanced additive that maintains robust wear protection. When you want to extend the life of your high mileage engine and emission system and find out how many miles you can go on a high-mileage oil,ย there is no better choice than Castrolย GTX High Mileage Motor Oil.

Product Features:
  • Phosphorus replacement technology to help extend the life of the emission system
  • Superior dispersancy that fights sludge build up
  • Exceptional oil burn-off protection exceeding industry standards (based on api and acea volatility specifications)
  • Improved fuel economy (in 5w-20, 5w-30 and 10w-30 grades versus industry specifications)
  • Provides extra protection for older vehicles: Castrol GTX High Mileage Engine Oil is specifically designed to provide extra protection for high mileage engines, helping to extend the life of your vehicle.
  • Synthetic blend composition: This engine oil is a synthetic blend, combining the benefits of both conventional and synthetic oils to provide superior protection against sludge, wear, and burn-off.
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Castrol – EDGE 5W-30 Advanced Full Synthetic Engine Oil: 5 Quart (Part No.1598B1)

EDGE 5W-30 Advanced Full Synthetic Engine Oil: 5 Quart

from

$37.99
Castrol EDGE with Fluid TITANIUM Technology is Castrol’s strongest oil and the natural choice for drivers who want the best combination of sludge protection, wear protection and maximum engine performance. Unlock maximum performance with every drive. Today’s engines are smaller, more powerful and under more pressure than ever before. Castrol EDGE has been engineered to withstand the stress of modern engines and provides 10X better high temperature performance than the latest industry standard. Did you know that friction can waste up to 10% of an engine’s performance? Increased demands placed on the engine to deliver power and fuel efficiency create intense friction between critical engine parts. Castrol EDGE transforms its structure under pressure to keep metal apart and reduce friction for maximum engine performance and delivers 6X better wear protection than required by the latest Sequence IVA test limits.

Product Features:
  • 3x stronger against viscosity breakdown than leading full synthetic (based on kurt orbahn test in 5W-30 grade)
  • 10x better high temperature performance (as measured in sequence iiih engine test vs. api sp test limit)
  • 6x better wear protection
  • 1.4x better sludge protection (as measured in sequence vh engine test vs. api sp test limit)
  • Full Synthetic Oil Composition: Castrol EDGE w/SPT Engine Oil is a full synthetic oil that contains new powerful dispersant molecules, providing superior engine protection and performance.
  • Strongest Oil: Castrol EDGE with Fluid TITANIUM Technology is Castrol’s strongest oil, providing the best combination of sludge protection, wear protection, and maximum engine performance.
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Castrol – GTX 10W-30 High Mileage Synthetic Blend Motor Oil: 5 Quart (Part No.1597B0)

GTX 10W-30 High Mileage Synthetic Blend Motor Oil: 5 Quart

from

$30.99
Castrol GTX High Mileage motor oil is the leading consumer high-mileage brand. You won’t need to worry about using a high mileage oil or synthetic because this is both. It’s aย synthetic blend engine oilย that helps extend the life of your engine by protecting against sludge, wear and burn-off and also liquid engineered to protect your emission system. One of the leading causes of ‘check engine’ lights coming on in high mileage cars is actually catalytic converter failure, which can be caused by phosphorous in engine oil. While phosphorous is present in all engine oils for its ability to reduce wear, it is effectively poisonous to catalytic converters. Castrolย GTX High Mileage Motor Oil is liquid engineered with Phosphorous Replacement Technology to replace some of the phosphorous with an advanced additive that maintains robust wear protection. When you want to extend the life of your high mileage engine and emission system and find out how many miles you can go on a high-mileage oil,ย there is no better choice than Castrolย GTX High Mileage Motor Oil.

Product Features:
  • Phosphorus Replacement Technology to help extend the life of the emission system
  • Superior dispersancy that fights sludge build up
  • Exceptional oil burn-off protection exceeding industry standards (Based on API and ACEA volatility specifications)
  • Improved fuel economy (In 5W-20, 5W-30 and 10W-30 grades versus industry specifications)
  • Synthetic Blend Composition: Castrol GTX High Mileage Motor Oil is a synthetic blend, offering the benefits of both conventional and synthetic oils for superior engine protection.
  • Extended Engine Life: Designed to protect against sludge, wear, and burn-off, this motor oil helps extend the life of high mileage engines.
  • Optimal Viscosity: With an SAE oil weight of 10W-30, this motor oil provides excellent performance in a wide range of temperatures, ensuring reliable engine protection.
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Castrol – EDGE 5W-30 Advanced Full Synthetic Motor Oil: 1 Quart (Part No.152C3C)

EDGE 5W-30 Advanced Full Synthetic Motor Oil: 1 Quart

from

$11.99
Castrol EDGE with Fluid TITANIUM Technology is Castrol’s strongest oil and the natural choice for drivers who want the best combination of sludge protection, wear protection and maximum engine performance. Unlock maximum performance with every drive. Today’s engines are smaller, more powerful and under more pressure than ever before. Castrol EDGE has been engineered to withstand the stress of modern engines and provides 10X better high temperature performance than the latest industry standard. Did you know that friction can waste up to 10% of an engine’s performance? Increased demands placed on the engine to deliver power and fuel efficiency create intense friction between critical engine parts. Castrol EDGE transforms its structure under pressure to keep metal apart and reduce friction for maximum engine performance and delivers 6X better wear protection than required by the latest Sequence IVA test limits.

Product Features:
  • 3X Stronger against viscosity breakdown than leading full synthetic (Based on Kurt Orbahn test in 5W-30 grade)
  • 10X Better High Temperature performance (As measured in Sequence IIIH engine test vs. API SP test limit)
  • 6X Better Wear Protection
  • 1.4X Better Sludge Protection (As measured in Sequence VH engine test vs. API SP test limit)
  • Advanced Friction Reduction: Transforms its structure under pressure to keep metal parts apart, reducing friction and unlocking maximum engine performance, which can help prevent up to 10% performance loss due to friction.
  • Engineered for Modern Engines: Specially designed to withstand the stress of today’s smaller, more powerful engines, ensuring optimal performance and protection under increased pressure and demands.
  • Full Synthetic Composition: As a full synthetic motor oil with a 5W-30 SAE oil weight, Castrol EDGE offers superior protection and performance, making it the natural choice for drivers seeking the best for their vehicles.
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Castrol – EDGE High Mileage 5W-30 Full Synthetic Engine Oil 1 Quart (Part No.15979F)

EDGE High Mileage 5W-30 Full Synthetic Engine Oil 1 Quart

from

$12.99
CASTROL EDGE High Mileage 5W-30 Full Synthetic Motor Oil 1 Quart is the perfect choice for vehicles with over 75K miles. It is formulated with Fluid Titanium Technology that provides 10X better high-temperature performance and 6X better wear protection. The oil is designed with Phosphorus Replacement Technology that preserves the catalytic converter and the emission system. It meets API SP/SN PLUS, ILSAC GF-6, GM dexos1 Gen 2, and other OEM specifications. Castrol EDGE High Mileage is a full synthetic motor oil that offers superior performance and protection for high mileage engines. It is available in different grades, including 5W-20, 5W-30, and 10W-30. Try Castrol EDGE High Mileage today and extend the life of your engine.

Product Features:
  • 10x better high temperature performance – as measured in seq iiih engine test vs. api sp limit
  • 6x better wear protection – as measured in seq iva test vs. latest test limit
  • From the makers of the No. 1 high mileage brand
  • Meets api sp/sn plus, ilsac gf-6, gm dexos1 gen 2, meets ford wss-m2c961-a1 and wss-m2c946-b1, meets engine test requirements of chrysler ms 6395 and 13340
  • Castrol edge offers engine oils that meet oem specification approvals or licenses that cover over 97.3% of the us car parc.
  • Available in the following grades: 5w-20, 5w-30, 10w-30, and 10w-40
  • Try castrol edge high mileage today
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Castrol – GTX Ultraclean 5W-30 Synthetic Blend Motor Oil: 5 Quart (Part No.15A66D)

GTX Ultraclean 5W-30 Synthetic Blend Motor Oil: 5 Quart

from

$29.99
Environmental factors such as poor fuel quality, hot weather and stop-start driving conditions can lead to sludge, varnish and carbon build-up in your engine: three factors that reduce engine life, power and fuel economy. Castrol Ultraclean is a synthetic blend engine oil available in 0W-20, 5W-20 and 5W-30 grades. Its double-action formula has been proven to clean away the sludge that can block engine oilways* and helps prevent new sludge formation thanks to its synthetic technology. In fact, it provides up to 1.4X better sludge protection than is demanded by the latest industry standard. If keeping your engine clean is important to you, it’s good to know that no other oil keeps engines cleaner.

Product Features:
  • 1.4X superior sludge protection compared to tough industry standards (As measured in the Sequence VH Sludge test vs. API SP test limits)
  • Advanced protection against viscosity and thermal breakdown
  • Superior protection against high-temperature deposits
  • Premium-quality base oils and anti-wear additives that help extend the life of your engine
  • Double-Action Formula: The synthetic blend engine oil features a double-action formula that effectively cleans away existing sludge and prevents new sludge formation.
  • Versatile Grade Options: Available in 0W-20, 5W-20, and 5W-30 grades, Castrol Ultraclean offers flexibility to suit various engine requirements.
  • Enhanced Engine Performance: By reducing sludge, varnish, and carbon build-up, this oil helps improve engine life, power, and fuel economy.
  • Synthetic Blend Composition: The GTX Ultraclean 5W-30 Synthetic Blend Motor Oil combines the benefits of synthetic technology with the reliability of a standard oil class.
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Castrol – GTX High Mileage Synthetic Blend 5W-30 Engine Oil: Helps Protect Emission Systems, 1 Quart (Part No.149D6A)

GTX High Mileage Synthetic Blend 5W-30 Engine Oil: Helps Protect Emission Systems, 1 Quart

from

$10.49
Castrol GTX High Mileage motor oil is the leading consumer high-mileage brand. It’s aย synthetic blend motor oil that helps extend the life of your engine by protecting against sludge, wear and burn-off. Castrol GTX High Mileage is also engineered to protect your emission system. One of the leading causes of ‘check engine’ lights coming on in high mileage cars is catalytic converter failure, which can be caused by phosphorous in engine oil. While phosphorous is present in all engine oils for its ability to reduce wear, it is effectively poisonous to catalytic converters. Castrolย GTX High Mileage is formulated with Phosphorous Replacement Technology to replace some of the phosphorous with an advanced additive that maintains robust wear protection. When you want to extend the life of your high mileage engine and emission system, there is no better choice than Castrolย GTX High Mileage.

Product Features:
  • Phosphorus replacement technology to help extend the life of the emission system
  • Superior dispersancy that fights sludge build up
  • Exceptional oil burn-off protection exceeding industry standards (based on api and acea volatility specifications)
  • Seal conditioners to help reduce leaks
  • Advanced additives that minimize engine wear
  • Improved fuel economy (in 5w-20, 5w-30 and 10w-30 grades versus industry specifications)
  • Meets or exceeds api sp/sn plus/sn, ilsac gf-6 and latest ford specs
See More

Castrol – GTX 10W-30 Conventional Motor Oil, Helps Extend Engine Life, 5 Quart (Part No.15B7AA)

GTX 10W-30 Conventional Motor Oil, Helps Extend Engine Life, 5 Quart

from

$29.99
Sludge can block your engine’s vital oilways like cholesterol and if untreated, can rob an engine of its power and ultimately its life. Castrol GTX is a premium conventional motor oil that has been helping to extend engine life for over 50 years. It has evolved to meet the needs of consumers and vehicle manufacturers since 1968 and continues to innovate and remain a trusted brand today. Severe driving conditions such as heavy traffic, poor fuel quality, harsh driving conditions and exceeding oil change intervals can all cause the build-up of a thick, tar like substance called sludge. If untreated, it can rob a car’s engine of its power and ultimately its life. GTX is specially engineered to prevent harmful build-up of sludge while protecting against newย oil splatter formation better than tough industry standards. Help Extend the Life of Your Engine with Castrol GTX.

Product Features:
  • Superior protection against engine sludge (When tested in engines with a high level of sludge)
  • Advanced protection against viscosity and thermal breakdown
  • Premium quality base oils and anti-wear additives to help extend the life of your engine
  • Helps minimize oil consumption
  • Proven Longevity: With over 50 years of innovation and trust, Castrol GTX helps extend the life of your engine by protecting against new oil splatter formation better than tough industry standards.
  • Adaptable to Severe Conditions: Designed to perform under severe driving conditions such as heavy traffic, poor fuel quality, and harsh driving environments, ensuring your engine remains powerful and reliable.
  • Premium Conventional Oil: As a premium conventional motor oil, Castrol GTX meets the needs of both consumers and vehicle manufacturers, providing reliable performance and protection.
  • Optimal Viscosity: Featuring an SAE oil weight of 10W-30, Castrol GTX offers optimal viscosity for a wide range of temperatures, ensuring smooth engine operation and protection.
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Valvoline – Full Synthetic High Mileage with MaxLife Technology 10W-30 Engine Oil: Maximizes Engine Life, 5 Quart (Part No.881170)

Full Synthetic High Mileage with MaxLife Technology 10W-30 Engine Oil: Maximizes Engine Life, 5 Quart

from

$37.99
Upgrading your motor oil to Valvoline Full Synthetic High Mileage with MaxLife Technology can help you increase the longevity of your car, truck or SUV with over 75,000 miles. It’s proven to protect your high-mileage motor against wear, friction, heat, and deposits – the leading causes of engine breakdown and expensive repairs. Our exclusive formulation goes beyond industry standards to protect your engine. It’s fortified with enhanced wear additives and friction-fighting agents to safeguard critical engine components, extra detergents to clean inside your engine, and premium seal conditioners to restore aging seals and prevent leaks. Superior viscosity modifiers and high-quality base oils help it perform exceptionally in both high and low temperatures. Engineered with ingenuity, tested with tenacity, and proven with purpose, our formula was innovated in America with a century and a half of hands-on experience from the original motor oil brand.

Product Features:
  • Enhanced maxlife technology prevents engine breakdown in extreme conditions with 50% better wear protection than the industry standard
  • Treat and prevent leaks with premium seal conditioners to keep oil out of places it shouldn’t be
  • 25% extra defense against deposits, sludge, corrosion and rust via interior-cleansing detergents
  • Extreme temperature protection through our high-quality base oils and superior viscosity modifiers
  • Meets or exceeds all requirements of ilsac gf-6a, api sp, api sn with sn plus, api sn
  • High Mileage Protection: Valvoline Full Synthetic High Mileage Engine Oil is specially designed to protect engines with over 75,000 miles against wear, friction, heat, and deposits, ensuring a longer lifespan for your vehicle.
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Castrol – EDGE Euro Car A3/B4 5W-30 Full Synthetic Motor Oil, 1 Quart (Part No.15484E)

EDGE Euro Car A3/B4 5W-30 Full Synthetic Motor Oil, 1 Quart

from

$12.49
Castrol EDGE Euro Car 5W-30 A3/B4 Full Synthetic Motor Oil transforms under pressure, increasing film strength to prevent oil breakdown and reduce friction, unlocking maximum performance. Optimized to deliver 40% better performance than required by ACEA standards, it is recommended by world-leading auto manufacturers. This full-synthetic oil provides engine protection for the entire drain interval, even under the extreme pressure of high-output engines. Formulated for the latest technology, high-output engines that operate at extreme temperatures, it meets API CF/SL, ACEA A3/B4, BMW LL 01, Ford WSS-M2C937-A, MB Approval 229.3/229.5, Porsche A40, and VW 502 00/505 00 specifications, covering European OEM gasoline requirements for BMW, Mercedes-Benz, Porsche, and VW/Audi.

Product Features:
  • Optimized to deliver 40% better performance than required by ACEA standards
  • Recommended by world leading auto manufacturers
  • Engine protection for the entire drain interval even under extreme pressure of high output engines
  • Meets API CF/SL, ACEA A3/B4, BMW LL 01, Meets Ford WSS-M2C937-A, MB Approval 229.3/229.5, Porsche A40, VW 502 00/505 00
  • Advanced Formulation: Specifically formulated for the latest technology, high-output engines that operate at extreme temperatures, ensuring reliable performance.
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Castrol – EDGE Euro Car 5W-30 C3 Full Synthetic Engine Oil 1 Quart (Part No.154BC4)

EDGE Euro Car 5W-30 C3 Full Synthetic Engine Oil 1 Quart

from

$12.49
CASTROL EDGE Euro Car 5W-30 C3 Full Synthetic Motor Oil is a high-performance engine oil that is designed to provide superior protection to the latest technology, high output engines that operate at extreme temperatures. This full-synthetic motor oil is formulated to transform under pressure, increasing film strength to prevent oil breakdown and reduce friction to unlock maximum performance. It is optimized to deliver 40% better performance than other motor oils and is recommended by world-leading auto manufacturers. This motor oil provides engine protection for the entire drain interval and meets API CF/SN, ACEA A3/B4, ACEA C3, GM dexos2 specifications. It is suitable for European OEM diesel specifications for Mercedes-Benz and VW/Audi. This motor oil was formerly known as Castrol SLX and is available in a 1-quart container.

Product Features:
  • Optimized to deliver 40% better performance than required by acea standards
  • Recommended by world leading auto manufacturers
  • Engine protection for the entire drain interval even under extreme pressure of high output engines
  • Meets api cf/sn, acea a3/b4, acea c3, gm dexos2, mb approval 229.31/229.51, vw 505 00/505 01, renault rn 0700/0710
  • Formerly known as castrol slx
  • Syntec Power Technology: The reformulated EDGE Engine Oil now features Syntec Power Technology, which enhances its performance even further.
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Castrol – GTX Ultraclean 5W-30 Synthetic Blend Motor Oil: No Oil Keeps Engines Cleaner, 1 Quart (Part No.15A66C)

GTX Ultraclean 5W-30 Synthetic Blend Motor Oil: No Oil Keeps Engines Cleaner, 1 Quart

from

$9.99
Castrolยฎ Ultraclean synthetic blend engine oil is our cleanest GTX ever. Environmental factors such as poor fuel quality, hot weather and stop-start driving conditions can lead to the buildup of sludge that can reduce engine life, power and fuel economy. Castrol Ultraclean has a double-action formula proven to clean away the sludge that can block engine oilways and helps prevent new sludge formation from occurring. In fact, it provides up to 1.4X better sludge protection than is demanded by the latest industry standard (as measured in the Sequence VH Sludge test vs. API SP test limits). No other oil keeps engines cleaner.

Product Features:
  • Premium-quality base oils and anti-wear additives that help extend the life of your engine
  • 1.4X superior sludge protection compared to tough industry standards, as measured in the Sequence VH Sludge test vs. API SP test limits
  • Advanced protection against viscosity and thermal breakdown
  • Superior protection against high-temperature deposits
  • Meets or exceeds API SP/SN PLUS/SN, ILSAC GF-6 and latest Ford specs
  • Double-Action Formula: Castrol Ultraclean’s unique double-action formula effectively cleans away existing sludge and prevents new sludge formation, ensuring optimal engine performance.
  • Enhanced Engine Life and Performance: Designed to combat environmental factors like poor fuel quality, hot weather, and stop-start driving conditions, which can reduce engine life, power, and fuel economy.
  • Synthetic Blend Composition: Combines the benefits of synthetic and conventional oils, offering superior protection and performance in a 5W-30 SAE oil weight.
  • Cleanest GTX Ever: Marketed as Castrol’s cleanest GTX oil, ensuring that no other oil keeps engines cleaner, making it an ideal choice for maintaining engine cleanliness and efficiency.
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Castrol – GTX 10W-30 Conventional Motor Oil, Extends Engine Life, 1 Quart (Part No.15B400)

GTX 10W-30 Conventional Motor Oil, Extends Engine Life, 1 Quart

from

$9.99
Sludge can block your engine’s vital oilways like cholesterol and if untreated, can rob an engine of its power and ultimately its life. Castrol GTX is a premium conventional motor oil that has been helping to extend engine life for over 50 years. It has evolved to meet the needs of consumers and vehicle manufacturers since 1968 and continues to innovate and remain a trusted brand today. Severe driving conditions such as heavy traffic, poor fuel quality, harsh driving conditions and exceeding oil change intervals can all cause the build-up of a thick, tar like substance called sludge. If untreated, it can rob a car’s engine of its power and ultimately its life. GTX is specially engineered to prevent harmful build-up of sludge while protecting against newย oil splatter formation better than tough industry standards. Help Extend the Life of Your Engine with Castrol GTX.

Product Features:
  • Superior protection against engine sludge (When tested in engines with a high level of sludge)
  • Advanced protection against viscosity and thermal breakdown
  • Premium quality base oils and anti-wear additives to help extend the life of your engine
  • Helps minimize oil consumption
  • Trusted Brand: With over 50 years of innovation and trust, Castrol GTX has evolved to meet the needs of both consumers and vehicle manufacturers since 1968.
  • Adaptable to Severe Conditions: Designed to perform under severe driving conditions such as heavy traffic, poor fuel quality, and harsh driving environments.
  • This premium conventional motor oil, with an SAE oil weight of 10W-30, meets the standard oil class requirements for a wide range of vehicles.
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Castrol – GTX High Mileage Synthetic Blend 10W-30 Motor Oil: Helps Protect Emission Systems, 1 Quart (Part No.149D6C)

GTX High Mileage Synthetic Blend 10W-30 Motor Oil: Helps Protect Emission Systems, 1 Quart

from

$10.49
Castrolยฎ GTXยฎ High Mileage motor oil is the leading consumer high-mileage brand. It’s aย synthetic blend motor oil that helps extend the life of your engine by protecting against sludge, wear and burn-off. Castrol GTX High Mileage is also engineered to protect your emission system. One of the leading causes of ‘check engine’ lights coming on in high mileage cars is catalytic converter failure, which can be caused by phosphorous in engine oil. While phosphorous is present in all engine oils for its ability to reduce wear, it is effectively poisonous to catalytic converters. Castrolย GTX High Mileage is formulated with Phosphorous Replacement Technology to replace some of the phosphorous with an advanced additive that maintains robust wear protection. When you want to extend the life of your high mileage engine and emission system, there is no better choice than Castrolย GTX High Mileage.

Product Features:
  • Phosphorus Replacement Technology to help extend the life of the emission system
  • Superior dispersancy that fights sludge build up
  • Exceptional oil burn-off protection exceeding industry standards (based on API and ACEA volatility specifications)
  • Seal conditioners to help reduce leaks
  • Advanced additives that minimize engine wear
  • Improved fuel economy (in 5W-20, 5W-30 and 10W-30 grades versus industry specifications)
  • Meets or exceeds API SP/SN PLUS/SN and ILSAC GF-6 specs
  • Engine Longevity: Castrol GTX High Mileage motor oil is specifically designed to extend the life of high mileage engines by protecting against sludge, wear, and burn-off.
  • Emission System Protection: Engineered to safeguard your emission system, this motor oil helps prevent catalytic converter failure, a common cause of ‘check engine’ lights in high mileage vehicles.
  • Synthetic Blend Composition: This 10W-30 synthetic blend motor oil offers superior performance and protection compared to conventional oils, making it ideal for high mileage engines.
  • Trusted Brand: As a leading consumer high-mileage brand, Castrol GTX High Mileage provides reliable and effective engine protection, ensuring your vehicle runs smoothly for longer.
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Castrol – EDGE 10W-30 Full Synthetic Motor Oil, 5 Quart (Part No.1598B6)

EDGE 10W-30 Full Synthetic Motor Oil, 5 Quart

from

$37.99
Castrol EDGE 10W-30 Full Synthetic Motor Oil is Castrol’s strongest oil, ideal for drivers seeking the best in sludge protection, wear protection, and maximum engine performance. This oil is 3X stronger against viscosity breakdown than the leading full synthetic, 10X better in high-temperature performance, and offers 6X better wear protection. It meets API SP/SN PLUS, ILSAC GF-6, ACEA A1/B1, GM 6094M, and 4718M standards, and fulfills the engine test requirements of Chrysler MS 6395, ensuring top-tier performance and reliability. Unlock maximum performance with every drive.

Product Features:
  • 3X Stronger against viscosity breakdown than the leading full synthetic – Based on Kurt Orbahn test in 5W-30 grade
  • 10X Better High Temperature performance – As measured in Seq IIIH engine test vs. API SP limit
  • 6X Better Wear Protection – As measured in Seq IVA test vs. latest test limit
  • Meets API SP/SN PLUS, ILSAC GF-6, ACEA A1/B1, GM 6094M and 4718M, Meets engine test requirements of Chrysler MS 6395
  • Advanced Fluid TITANIUM Technology: Incorporates Fluid TITANIUM Technology, making it Castrol’s strongest oil for drivers who demand the best in sludge protection, wear protection, and maximum engine performance.
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Valvoline – Advanced Full Synthetic 10W-30 Motor Oil: Maximizes Engine Life, 5 Quart (Part No.881165)

Advanced Full Synthetic 10W-30 Motor Oil: Maximizes Engine Life, 5 Quart

from

$36.99
Today’s advanced engine technology requires advanced protection. Valvoline Advanced Full Synthetic, the motor oil designed to protect today’s sophisticated engines, contains premium anti-wear additives, superior antioxidants and extra detergents. It protects 40% better against wear, resists oil breakdown 10-times better, and defends 25% more against deposits than industry standards for maximum performance and engine longevity. And with an exceptional range of temperature protection your engine will ready for extreme weather. Valvoline invented motor oil 150 years ago, and we’ve been reinventing it ever since. Get Valvoline Advanced Full Synthetic and give your engine the advanced protection proven to maximize engine life.

Product Features:
  • ADVANCED PROTECTION AGAINST the four main causes of engine breakdown: wear friction heat and deposits
  • 40% BETTER WEAR PROTECTION vs. industry standard as tested in the Sequence IVB engine test
  • 25% BETTER DEPOSIT PROTECTION with superior engine cleaning detergents as tested in the GMOD engine test
  • EXCEPTIONAL HIGH/LOW TEMPERATURE PROTECTION defends your motor no matter the weather conditions
  • MEETS OR EXCEEDS ALL REQUIREMENTS of ILSAC GF-6A, API SP, API SN with SN PLUS, API SN
  • Enhanced Oil Stability: Resists oil breakdown 10-times better than industry standards, providing consistent performance and reliability.
  • Premium Additives: Contains premium anti-wear additives, superior antioxidants, and extra detergents for maximum performance and engine longevity.
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Castrol – GTX Conventional 20W-50 Engine Oil: Helps Protect Against Sludge Build Up, 5 Quart (Part No.15984B)

GTX Conventional 20W-50 Engine Oil: Helps Protect Against Sludge Build Up, 5 Quart

from

$29.99
Castrol GTX is a premium conventional motor oil that has been helping to extend engine life for over 50 years. It continues to innovate to meet the needs of consumers and vehicle manufacturers and remains among the most trusted brands today. Severe driving conditions such as heavy traffic, poor fuel quality, harsh driving conditions and exceeding oil change intervals can all cause the build-up of a thick, tar like substance called sludge. If not addressed, it can rob a car’s engine of its power and ultimately its life. GTX is specially engineered to prevent harmful build-up of sludge while protecting against newย oil splatter formation better than tough industry standards.

Product Features:
  • Premium quality base oils and anti-wear additives to help extend the life of your engine
  • Advanced protection against viscosity and thermal breakdown
  • Superior protection against engine sludge (when tested in engines with a high level of sludge)
  • Helps minimize oil consumption
  • Meets ilsac gf-6 specs
  • Unsurpassed thermal breakdown protection: GTX Engine Oil, 20W50 provides superior protection against thermal breakdown, ensuring that your engine stays cool and runs smoothly even under extreme conditions.
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Castrol – EDGE 10W-30 Full Synthetic Motor Oil, 1 Quart (Part No.152E4E)

EDGE 10W-30 Full Synthetic Motor Oil, 1 Quart

from

$11.99
Castrol EDGE 10W-30 Full Synthetic Motor Oil is Castrol’s strongest oil, ideal for drivers seeking the ultimate in sludge protection, wear protection, and engine performance. This oil is 3X stronger against viscosity breakdown than the leading full synthetic, 10X better in high-temperature performance, and offers 6X better wear protection. It meets API SP/SN PLUS, ILSAC GF-6, ACEA A1/B1, GM 6094M and 4718M, and Chrysler MS 6395 engine test requirements, ensuring top-tier performance and reliability. Unlock maximum performance with every drive.

Product Features:
  • 3X Stronger against viscosity breakdown than the leading full synthetic – Based on Kurt Orbahn test in 5W-30 grade
  • 10X Better High Temperature performance – As measured in Seq IIIH engine test vs. API SP limit
  • 6X Better Wear Protection – As measured in Seq IVA test vs. latest test limit
  • Meets API SP/SN PLUS, ILSAC GF-6, ACEA A1/B1, GM 6094M and 4718M, Meets engine test requirements of Chrysler MS 6395
  • Ultimate Sludge and Wear Protection: Castrol EDGE 10W-30 Full Synthetic Motor Oil with Fluid TITANIUM Technology offers superior protection against sludge and wear, ensuring your engine remains clean and efficient.
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Valvoline – High Mileage with MaxLife Technology Synthetic Blend 10W-30 Engine Oil: Maximize Engine Life, 1 Quart (Part No.797976)

High Mileage with MaxLife Technology Synthetic Blend 10W-30 Engine Oil: Maximize Engine Life, 1 Quart

from

$9.99
75,000 miles is more than a mile marker. It’s a signal that your engine is ready for greater protection. That’s when you need Valvoline High Mileage with MaxLife Technology Motor Oil. Its exclusive formula is proven to maximize engine life in cars, trucks, and SUVs with over 75,000 miles. Our mixture is specially developed with a unique combination of synthetic and premium conventional oils to protect your high-mileage motor against wear, friction, heat, and deposits – the four major causes of engine breakdown and expensive repairs. Anti-wear additives defend critical engine components, advanced friction-fighting agents reduce heat and abrasion, added detergents clean the inside of your engine, and premium seal conditioners handle aging seals to prevent leaks. It fights sludge, corrosion and rust that can rob your engine of horsepower, fuel efficiency and longevity. From extreme temperatures and cold starts to stop-and-go traffic and frequent short trips, viscosity modifiers make sure the oil flows more easily, coats more completely, and resists thermal breakdown under even the most intense driving conditions. Its unique mixture curbs contaminants to keep high-mileage engines from burning and consuming oil that can foul spark plugs, creating higher emissions and causing your motor to run roughly.

Product Features:
  • Maxlife technology prevents engine breakdown with 40% better wear protection than the industry standard
  • Refresh aging seals and prevent leaks with seal conditioners
  • Reduce sludge, deposits, corrosion, and rust with added detergents – keep motors clean inside
  • Enhanced friction performance helps maximize power with advanced friction-fighting agents
  • Meets or exceeds all requirements of ilsac gf-6a, api sp, api sn with sn plus, api sn
  • MaxLife High Mileage Synthetic Blend Engine Oil is specially designed for engines with over 75,000 miles, providing greater protection and maximizing engine life.
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Castrol – GTX 20W-50 Conventional Motor Oil: Helps Protect Against Sludge Build Up, 1 Quart (Part No.151A8E)

GTX 20W-50 Conventional Motor Oil: Helps Protect Against Sludge Build Up, 1 Quart

from

$9.99
Castrolยฎ GTXยฎ is a premium conventional motor oil that has been helping to extend engine life for over 50 years. It continues to innovate to meet the needs of consumers and vehicle manufacturers and remains among the most trusted brands today. Severe driving conditions such as heavy traffic, poor fuel quality, harsh driving conditions and exceeding oil change intervals can all cause the build-up of a thick, tar like substance called sludge. If not addressed, it can rob a car’s engine of its power and ultimately its life. GTX is specially engineered to prevent harmful build-up of sludge while protecting against newย oil splatter formation better than tough industry standards.

Product Features:
  • Premium quality base oils and anti-wear additives to help extend the life of your engine
  • Advanced protection against viscosity and thermal breakdown
  • Superior protection against engine sludge (when tested in engines with a high level of sludge)
  • Helps minimize oil consumption
  • Meets ILSAC GF-6 specs
  • Superior Performance: Exceeds tough industry standards in protecting against new oil splatter formation, providing superior performance and reliability.
  • Versatile Use: Suitable for a variety of driving conditions including heavy traffic, poor fuel quality, and harsh environments, making it a versatile choice for many vehicles.
  • High-Quality Composition: This conventional motor oil with SAE weight 20W-50 offers robust protection and performance, maintaining engine health and efficiency.
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Castrol – GTX Conventional 10W-40 Motor Oil: Helps Protect Against Sludge Build Up, 1 Quart (Part No.14CD5A)

GTX Conventional 10W-40 Motor Oil: Helps Protect Against Sludge Build Up, 1 Quart

from

$9.99
Castrolยฎ GTXยฎ is a premium conventional motor oil that has been helping to extend engine life for over 50 years. It continues to innovate to meet the needs of consumers and vehicle manufacturers and remains among the most trusted brands today. Severe driving conditions such as heavy traffic, poor fuel quality, harsh driving conditions and exceeding oil change intervals can all cause the build-up of a thick, tar like substance called sludge. If not addressed, it can rob a car’s engine of its power and ultimately its life. GTX is specially engineered to prevent harmful build-up of sludge while protecting against newย oil splatter formation better than tough industry standards.

Product Features:
  • Premium quality base oils and anti-wear additives to help extend the life of your engine
  • Advanced protection against viscosity and thermal breakdown
  • Superior protection against engine sludge (when tested in engines with a high level of sludge)
  • Helps minimize oil consumption
  • Meets ILSAC GF-6 specs
  • Engine Life Extension: Castrolยซ GTXยซ has been helping to extend engine life for over 50 years, making it one of the most trusted motor oil brands today.
  • Conventional Oil Composition: As a premium conventional motor oil, Castrolยซ GTXยซ meets the needs of both consumers and vehicle manufacturers.
  • Superior Performance: Exceeds tough industry standards by protecting against new oil splatter formation, ensuring optimal engine performance.
  • Versatile SAE Weight: With an SAE oil weight of 10W-40, Castrolยซ GTXยซ is suitable for a wide range of vehicles, providing reliable protection and performance.
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Castrol – EDGE High Mileage 10W-30 Full Synthetic Engine Oil 1 Quart (Part No.15979B)

EDGE High Mileage 10W-30 Full Synthetic Engine Oil 1 Quart

from

$12.99
CASTROL EDGE High Mileage 10W-30 Full Synthetic Motor Oil 1 Quart is the perfect solution for vehicles with over 75K miles. It is formulated with Fluid Titanium Technology and Phosphorus Replacement Technology to provide 10X better high-temperature performance and 6X better wear protection. This motor oil meets API SP/SN PLUS, ILSAC GF-6, GM 6094M standards and offers motor oils that meet OEM specifications. It is available in different grades, including 5W-20, 5W-30, and 10W-30. This motor oil is the natural choice for consumers who want to extend maximum engine performance and preserve the catalytic converter and the emission system. Try CASTROL EDGE High Mileage today and experience the difference in your vehicle’s performance.

Product Features:
  • 10x better high temperature performance – as measured in seq iiih engine test vs. api sp limit
  • 6x better wear protection – as measured in seq iva test vs. latest test limit
  • From the makers of the No. 1 high mileage brand
  • Meets api sp/sn plus, ilsac gf-6, gm 6094m
  • Castrol edge offers engine oils that meet oem specification approvals or licenses that cover over 97.3% of the us car parc.
  • Available in the following grades: 5w-20, 5w-30, 10w-30, and 10w-40
  • Try castrol edge high mileage today
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Valvoline – Advanced Full Synthetic 10W-30 Motor Oil: Maximizes Engine Life, 1 Quart (Part No.VV935)

Advanced Full Synthetic 10W-30 Motor Oil: Maximizes Engine Life, 1 Quart

from

$11.49
Today’s advanced engine technology requires advanced protection. Valvoline Advanced Full Synthetic, the motor oil designed to protect today’s sophisticated engines, contains premium anti-wear additives, superior antioxidants and extra detergents. It protects 40% better against wear, resists oil breakdown 10-times better, and defends 25% more against deposits than industry standards for maximum performance and engine longevity. And with an exceptional range of temperature protection your engine will ready for extreme weather. Valvoline invented motor oil 150 years ago, and we’ve been reinventing it ever since. Get Valvoline Advanced Full Synthetic and give your engine the advanced protection proven to maximize engine life.

Product Features:
  • ADVANCED PROTECTION AGAINST the four main causes of engine breakdown: wear friction heat and deposits
  • 40% BETTER WEAR PROTECTION vs. industry standard as tested in the Sequence IVB engine test
  • 25% BETTER DEPOSIT PROTECTION with superior engine cleaning detergents as tested in the GMOD engine test
  • EXCEPTIONAL HIGH/LOW TEMPERATURE PROTECTION defends your motor no matter the weather conditions
  • MEETS OR EXCEEDS ALL REQUIREMENTS of ILSAC GF-6A, API SP, API SN with SN PLUS, API SN
  • Enhanced Oil Stability: This motor oil resists oil breakdown 10 times better than industry standards, providing consistent performance and reliability.
  • Premium Additives: Contains premium anti-wear additives, superior antioxidants, and extra detergents to maintain engine health and efficiency.
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Castrol – EDGE 10W-40 High Mileage Full Synthetic Motor Oil, 1 Quart (Part No.15989F)

EDGE 10W-40 High Mileage Full Synthetic Motor Oil, 1 Quart

from

$12.99
Castrol EDGE High Mileage 10W-40 Full Synthetic Motor Oil is specially formulated for vehicles with over 75K miles, making it the natural choice for consumers who want to extend maximum engine performance. Engineered with Phosphorus Replacement Technology to preserve the catalytic converter and the emission system, it offers 10X better high temperature performance and 6X better wear protection compared to industry standards. From the makers of the No. 1 High Mileage brand, this full synthetic oil meets API SP/SN PLUS specifications. Available in grades 5W-20, 5W-30, 10W-30, and 10W-40, Castrol EDGE High Mileage is the ultimate solution for maintaining your high-mileage vehicle.

Product Features:
  • 10X Better High Temperature performance – As measured in Seq IIIH engine test vs. API SP limit
  • 6X Better Wear Protection – As measured in Seq IVA test vs. latest test limit
  • From the makers of the No. 1 High Mileage brand
  • Meets API SP/SN PLUS
  • Castrol EDGE offers motor oils that meet OEM specification approvals or licenses that cover over 97.3% of the US car parc.
  • Available in the following grades: 5W-20, 5W-30, 10W-30, and 10W-40
  • Try Castrol EDGE High Mileage today
  • Specially formulated for vehicles with over 75K miles to extend maximum engine performance.
  • Engineered with Phosphorus Replacement Technology to preserve the catalytic converter and emission system.
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Castrol – Conventional 10W-40 Engine Oil – 5 Qt – Helps Extend Engine Life (Part No.15982E)

Conventional 10W-40 Engine Oil - 5 Qt - Helps Extend Engine Life

from

$31.99
Sludge can block your engine’s vital oilways like cholesterol and if untreated, can rob an engine of its power and ultimately its life. Castrol GTX is a premium conventional motor oil that has been helping to extend engine life for over 50 years. It has evolved to meet the needs of consumers and vehicle manufacturers since 1968 and continues to innovate and remain a trusted brand today. Severe driving conditions such as heavy traffic, poor fuel quality, harsh driving conditions and exceeding oil change intervals can all cause the build-up of a thick, tar like substance called sludge. If untreated, it can rob a car’s engine of its power and ultimately its life. GTX is specially engineered to prevent harmful build-up of sludge while protecting against newย oil splatter formation better than tough industry standards. Help Extend the Life of Your Engine with Castrol GTX.

Product Features:
  • Superior protection against engine sludge (when tested in engines with a high level of sludge)
  • Advanced protection against viscosity and thermal breakdown
  • Premium quality base oils and anti-wear additives to help extend the life of your engine
  • Helps minimize oil consumption
  • Unsurpassed thermal breakdown protection: GTX Engine Oil, 10W-40 provides superior protection against thermal breakdown, ensuring that your engine stays protected even under extreme temperatures.
  • Prevents harmful sludge build-up: GTX Engine Oil, 10W-40 is specially engineered to prevent the build-up of harmful sludge, which can rob your engine of its power and ultimately its life.
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Valvoline – High Mileage with MaxLife Technology Synthetic Blend 10W-30 Motor Oil: Maximize Engine Life, 5 Quart (Part No.779462)

High Mileage with MaxLife Technology Synthetic Blend 10W-30 Motor Oil: Maximize Engine Life, 5 Quart

from

$31.99
75,000 miles is more than a mile marker. It’s a signal that your engine is ready for greater protection. That’s when you need Valvoline High Mileage with MaxLife Technology Motor Oil. Its exclusive formula is proven to maximize engine life in cars, trucks, and SUVs with over 75,000 miles. Our mixture is specially developed with a unique combination of synthetic and premium conventional oils to protect your high-mileage motor against wear, friction, heat, and deposits – the four major causes of engine breakdown and expensive repairs. Anti-wear additives defend critical engine components, advanced friction-fighting agents reduce heat and abrasion, added detergents clean the inside of your engine, and premium seal conditioners handle aging seals to prevent leaks. It fights sludge, corrosion and rust that can rob your engine of horsepower, fuel efficiency and longevity. From extreme temperatures and cold starts to stop-and-go traffic and frequent short trips, viscosity modifiers make sure the oil flows more easily, coats more completely, and resists thermal breakdown under even the most intense driving conditions. Its unique mixture curbs contaminants to keep high-mileage engines from burning and consuming oil that can foul spark plugs, creating higher emissions and causing your motor to run roughly.

Product Features:
  • MAXLIFE TECHNOLOGY PREVENTS engine breakdown with 40% better wear protection than the industry standard
  • REFRESH AGING SEALS AND PREVENT LEAKS with seal conditioners
  • REDUCE SLUDGE, DEPOSITS, CORROSION, AND RUST with added detergents – keep motors clean inside
  • ENHANCED FRICTION PERFORMANCE HELPS MAXIMIZE POWER with advanced friction-fighting agents
  • MEETS OR EXCEEDS ALL REQUIREMENTS of ILSAC GF-6A, API SP, API SN with SN PLUS, API SN
  • MaxLife Technology: Valvoline High Mileage with MaxLife Technology is specially formulated to maximize engine life in vehicles with over 75,000 miles, providing superior protection against wear, friction, heat, and deposits.
  • Synthetic Blend Composition: This motor oil features a unique combination of synthetic and premium conventional oils, ensuring optimal performance and protection for high-mileage engines.
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Castrol – EDGE High Mileage 10W-30 Advanced Full Synthetic Engine Oil: 5 Qt (Part No.15906F)

EDGE High Mileage 10W-30 Advanced Full Synthetic Engine Oil: 5 Qt

from

$38.99
Castrol EDGE High Mileage with Fluid TITANIUM Technology is the natural choice for drivers who demand maximum performance from their high mileage cars, which often operate at extreme temperatures. Castrol EDGE High Mileage provides up to 10X better high temperature performance than the latest industry standard to ensure optimal protection and oil flow over the drive cycle. As your car ages, it can lose performance and efficiency and is also more prone to catalytic converter failure. Castrol EDGE High Mileage is liquid engineered with Phosphorous Replacement Technology to reduce harmful phosphorus to protect the catalytic converter and preserve the life of your emission system. Castrol EDGE High Mileage helps your car defy its miles and extend maximum performance.

Product Features:
  • Patented phosphorus replacement technology to help extend the life of your emission system
  • 10x better high temperature performance (as measured in sequence iiih engine test vs. api sp test limit)
  • 6x better wear protection (as measured in latest sequence iva engine test)
  • 1.4x better sludge protection (as measured in sequence vh engine test vs. api sp test limit)
  • Maximum Performance: Castrol EDGE High Mileage Engine Oil is designed to provide maximum performance for high mileage cars that often operate at extreme temperatures.
  • Improved High Temperature Performance: With up to 10X better high temperature performance than the latest industry standard, Castrol EDGE High Mileage Engine Oil ensures optimal protection and oil flow over the drive cycle.
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FAQs for 1985 Jeep J20 Engine Oil

What are the most popular Engine Oil for the 1985 Jeep J20?

With 3 brands you can trust, our most popular Engine Oil for the 1985 Jeep J20 parts are:
Full Synthetic 5W-30 Dexos1 Gen 3 Engine Oil: 5 Quart
from $27.99
This product is not rated
Full Synthetic 5W-30 Dexos1 Gen 3 Engine Oil: 5 Quart
Engine Oil

What are the best aftermarket Engine Oil for the 1985 Jeep J20?

See what past customers had to say about our highest-rated Engine Oil for the 1985 Jeep J20:
Advanced Full Synthetic 10W-30 Motor Oil: Maximizes Engine Life, 1 Quart
from $11.49
(690)
Advanced Full Synthetic 10W-30 Motor Oil: Maximizes Engine Life, 1 Quart
“I have always used Valvoline oil with very good luck so to find it at a very good price that’s great.”
EDGE 5W-30 Advanced Full Synthetic Motor Oil: 1 Quart
from $11.99
(442)
EDGE 5W-30 Advanced Full Synthetic Motor Oil: 1 Quart
“all my cars”