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ACDelco Iridium Spark Plug

(1237 reviews)
Part # 41-118
7 yr replacement if defective
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Product Information

Product Details
Part No. 41-118
Warranty Details (7 YR REPLACEMENT IF DEFECTIVE)
ACDelco GM Original Equipment Iridium Spark Plugs are designed, engineered, and tested to rigorous standards, and are backed by General Motors. They are our latest in spark plug technology and an exact replacement for your vehicle's original components. Iridium composition provides a high melting point and great strength, and provides excellent wear resistance and durability. ACDelco GM Original Equipment parts are the true OE parts installed during the production of or validated by General Motors for GM vehicles. Some ACDelco GM Original Equipment parts may have formerly appeared as GM Genuine Parts (OE) or ACDelco Professional.

Product Features:
  • Iridium is the latest in spark plug technology and is an exact replacement for vehicles original components
  • Iridium composition provides a high melting point and great strength, helps to provide excellent wear resistance and durability
  • Iridium offers excellent engine idle stability, reliable cold starting, quick acceleration and smooth performance
  • Three Piece Fired in Suppressor seal meters spark energy for long electrode life, helps prevent combustion leakage and helps block radio frequencies that can affect vehicle electronics
  • Iridium plugs are laser-welded which provides precision welds, reduces excess debris and wear rate, thus increasing durability
  • Some ACDelco GM Original Equipment parts may have formerly appeared as GM Genuine Parts (OE) or ACDelco Professional
  • ACDelco GM Original Equipment parts are designed, engineered and tested to rigorous standards, and are backed by General Motors.
  • GM Engineers design and validate OE parts specifically for your Chevrolet, Buick, GMC, or Cadillac vehicle
  • GM regularly updates production and service part designs to integrate new materials and technologies
Specifications
Ground Configuration:
Standard

Ground Electrode Tip Design:
Standard

Hex Size:
14 mm

Insulator Height:
2.067 in

Pre-Gap Size:
0.9 mm

Reach:
0.984 in

Thread Diameter:
0.551 in
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4.81 out of 5
1237 Customer Reviews
97% of respondents would recommend this to a friend
Ratings Distribution
5 Stars
1101
4 Stars
87
3 Stars
21
2 Stars
5
1 Star
23
They suckThey suckThey suck
I would buy this product againExactly what I orderedYep, i would buy againGreat plugs, great price.The right parts at the right price!
Pros
157
Improves Engine Efficiency
129
Increases Power
127
Easy To Install
115
Durable
30
Lightweight
Cons
12
none
7
Difficult To Install
7
No Improvement In Performance
1
Decreases Gas Mileage
1
Even New Parts Can Be Bad
Best Uses
176
Everyday Driving
138
Replacement
37
Performance Driving
24
Restoration
11
Racing
Car & Truck
24
Casual Driver
23
Auto Enthusiast
16
Truck Enthusiast
10
Mechanic
3
Competitive Driver
Describe Yourself
99
Casual Driver
65
Auto Enthusiast
40
Mechanic
32
Truck Enthusiast
9
Competitive Driver
Most Liked Positive Review
AC Delco spark plugs
This is the OEM replacement for my 1998 GMC Jimmy (and all the GM Vortec V6's out there). The original plugs were still running smoothly after 152,000 miles but the gas milage was dropping. You can't beat that kind of dependability or quality so why even look for an aftermarket plug. They have changed the design and part number from 41-992 (my old ones) to 41-993. These newer plugs have a tiny spark wire extending off of the center electrode instead of the flat rod. I guess this functions like a "lightning rod" and makes the spark more "focused". NOTE: these are the Professional Platinum plugs; HOWEVER, the box is marked Iridium. Theses are not suposed to be Iridium plugs and are pre-gapped just like a platinum plug should be (around 0.06 on the 41-993). Maybe someone can add a comment if they know something. Yes its the correct box, both the boxes and the plugs indicate 41-993. Whats up with that ? Installing a spark-plug is not hard, in principle, (loosen, remove, insert, tighten) but plugs on the Jimmy (Blazer or Bravada) are not a simple job because of their locations. Once you learn all the tricks its actually not so bad (except #3 plug, even after you know what to do its 10 minutes by itself). Yes these plugs cost a bit more (at list price) than some of the others but these are the plugs you want in your GM engine to get the optimum performance and longevity (unless you plan on re-engineering the entire ignition system with after-market performance parts). Use a coupon code at Advance Auto and you can get 40% off! Or just spend a couple of bucks now and be done with it, you don't want to do this plug change often. Unless you plan on modifing the entire ignition system just stick with what was designed for your motor. If these plugs run as well as the originals, they will outlast my ownership of the Jimmy (or me). I have seen the mpg increase to the level I originally had when I bought the Jimmy (23.5 mpg highway). With the old plugs, it had slowly been dropping off over the last 30,000 down to about 20.7 mpg. I should have done this job 3 years ago.
Most Liked Negative Review
Fine tune up, ready for another 50K
My old AC Delco spark plugs showed some usage at 50,000 miles. Mechanic said they could have gone the full 100,000 miles. However, I felt a tune up at 50,000 with the AC Delco spark plugs with Iridium would only improve my gas mileage and provide a better performaning vehicle. Tune up at 50,000 may have been overkill, but the ride is a smooth one.
Reviewed by 1237 Customers
The Premium Standard for GM vehicles
Staff Reviewer -
This is a great plug that will truly last 100k miles on a well-maintained vehicle. Stay away from knock-offs that claim greater HP and fuel savings for stock or midly modified vehicles.
Bottom Line Yes, I would recommend to a friend
great plug for my gm
Staff Reviewer -
works great in my 4.3 sonoma
Bottom Line Yes, I would recommend to a friend
ACDelco all the way
Staff Reviewer -
I recently did a tuneup with all ACDelco parts and couldn't be happier with the results. Just a warning: Don't try to gap these plugs, they are factory gapped.
Bottom Line Yes, I would recommend to a friend
STOCK PLUG WORK GREAT!!!!
Staff Reviewer -
DON'T WASTE YOUR $$$ ON ANY OTHER PLUGS!! STOCK SPARK WORK THE BEST !! I WASTED $$$ ON E3 PLUGS MISSED FIRED!& RAPID FIRE PLUGS MISSED FIRE TOO ! BUT STOCK PLUGS!!
Bottom Line Yes, I would recommend to a friend
AC Plugs Reliability
Staff Reviewer -
Great plugs!
Bottom Line Yes, I would recommend to a friend
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