ACDelco GM Original Equipment 41-110 Iridium Spark Plug

After 110,000 miles I decided it was time to replace the original spark plugs in my 2007 Chevrolet Express van. My original plugs were 41-985 which have been replaced by 41-110. Actually, GM usually suggests using 41-162 platinum plugs in cars 5+ years old instead of these iridium plugs. This has caused some confusion as to why. From what I can tell researching this, it is because the platinums aren't as expensive to make, and they don't expect older vechicles to last another 100K miles that the 41-110 is rated for. I keep cars forever so went with these 41-110 iridium plugs.Amazon sells genuine 41-110 plugs at a great price. The ones I got had consistent, correct gaps (0.04" for these) - do not try to adjust them or you could damage them - and looked a lot like the 41-985 plugs I took out, which still were in remarkably good condition and probably would have done fine another 50K miles!Warning:Beware getting your plugs elsewhere! Before finding these from amazon, I purchased a set claiming to be ACDelco 41-110 that were counterfeit. They were packaged in boxes with the ACDelco logo and the plugs were even marked ACDelco and Made in USA, but I later confirmed they were counterfeit plugs made in China. They also had different UPC codes on the boxes, and the outer electrodes didn't have a little metal circle at the spark point. Also the little center electrode, while similarly tapered, was fatter than on real ACDelco plugs. The fake plugs came in a box of 8 - genuine ACDelco now only comes in boxes of 4, or individually. The counterfeits had gaps ranging from 0.034 to 0.048. There are a lot of fake ones out these, so be careful! They usually won't last long or work as well and could even damage your vehicle.Installation tips:Installation isn't too bad for most DIYers. Replacing these in my 2007 Express 350 Passenger Van required taking off the glove compartment (4 hex head screws) to pull the inside engine cover off (4 latches). Push it to one side to access the plugs, though the front 2 are easier to get to from under the hood, after removing the coolant overflow reservoir (one bolt).I used a 5/8" spark plug socket, 3/8" ratchet wrench, a 1.5" extender and a locking 3" extender (which helps to get the socket back out after tightening a plug). Be careful and slowly wiggle the boots/wires off the plugs so you don't break the wires. I used 2 hands when I could, one on the metal sleeve part of the boot. Everything looked nice and clean so I didn't use any anti-seize or dielectric grease but some like to do that. Be careful not to push any debris into the plug hole or overtighten the new plugs. There should be a little click feeling when the boot is properly reseated on the plug. Takes about 1.5 hours total.Good luck!

Hope these aren't counterfeit as many on internet are, selling at low prices. Quality seems good and 2012 Sierra runs ok with them. Replacing these may have cleared up occasional miss but time will tell. They were gapped correctly out of box.

These are real plugs and not cheap Chinese counterfeit junk. I had to buy these to replace china knockoffs i was foolish enough to buy that lasted a whole 8k miles on two vehicles before all of them began fouling causing misfires. One electrode was actually missing. I did plenty of research on how to spot a fake and these are real. If the price is low so is the quality.

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Excellent performance and noticeable improvement in my 5.3l chevy avalanche. Checked gap and was spot on. I believe my gas milage increased by 1 - 2 mpg highway vs the original plugs with 105k miles. BTW, others have mentioned to use grease or lubricants on plug threads to make them easier to remove which is INCORRECT and NOT recommended by GM. This may result in over torque and potentially damaging the threads on your heads. Read your torque specs which are designated for dry threads only. Besides, this is an electrical connection which will work way better with metal on metal contact! Now on the electrode side and the wire boot do use a generous amount of dielectric grease. This will not only help maintain a good electric contact and keep moisture out but will also lube the boot and help push these on as these are tight especially with the heat shield on. This applies to gm vehicles especially the LS v8s (4.8, 5.3, 5.7, 6.0, 6.2, etc) Make sure you listen for the click to insure the wires are on all the way.

I am giving these three stars for a couple of reasons. First of all, I ordered 8 plugs and 1 out of those 8 the gap between the two electrodes was non existent. By this I mean the two were completely pressed together. I had to pry it apart. This brings me to my second point. Because of this I am sure the gap is off the required .40. I say that because now when idling the truck will jump in RPM's and then drop right back to where it is supposed to be. This wasn't an issue prior to changing the plugs. I didn't check the gap prior to installing because it was to my understanding that these are pre-gapped to .40. That, and I don't currently have the tool to do so. Now, I get to go buy one (only a couple dollars I know) but it's still the fact of the matter. Seem like solid plugs and the reviews are great. They are in much better shape than my last plugs. Just sort of irritated me that one of the plugs was clearly screwed up right out of the box.UPDATE: All plugs were gapped at .40 like they should have been. I still have a minor little hiccup at idle that I believe may be caused by wires. In any case, solid plugs. I will keep my review at 4/5 for the one plug that wasn't at all gapped.

Works great, no more idle miss in my 5.7L GM truck. Well, at 150K miles it was well past due (100K rec'd). I just bought the truck last fall and am now giving it a lot of TLC. several plugs were looking pretty tough with a fair amount of slag. It didn't seem to change MPG much yet, which I was hoping for. Wasn't real easy to change. It's hard to get to them all (hand and arm room) and I got scratched up pretty good. But, I saved perhaps $200. Don't forget to use a fender rug/guard, a step stool, blow away the debris before removing the plugs, be easy on the wires and use a little anti-seize on the threads. If you can understand all that you can most l handle this too. Having an after market manual is a big plus for me. They always pay for there costs in short order if your a DIYer looking for a few tips on how to do it right..Other tools used were std. (larger size) plug retaining socket, large ratchet, medium (~3") and med. long (~5") extensions.After jobs like this its easy to appreciate the jobs a good mechanic does.