Spark plug Denso or AC DELCO

Only use the factory AC-Delco 41-987 plugs.

I did swap in Denso IKH24 at APR recommendation. Runs nice and have no issues to share

Had these on my MKV and they made the car smoother too.

after installing the new plugs: 1- yes, the idle went down to around 780 (from 820-840) 2- the needle is rock steady.. you reeeeaaally have to fixate on it to see any fluctuation at all... 3- this is the weird one: power is smoother. Not "more power", but what I used to call "silky acceleration" when I raced Formula 5 years ago. hard to explain other than to say that the car outputs the same power without the drama, smooth... BTW, my car has 2100 miles on it.

Mine came out the box .028 and I left them as is. The plugs are 1 step colder so its already a plus. The car does run smoother through the rpm and does idle smoother.

I've had a slightly rough idle since my can was new (about 6500 miles now) Got an APR stage 1 tune a few months back and of course the idle was still rough. Finally got around to replacing the stock spark plugs with the APR recommended Denso IKH24 spark plugs and..... My idle is so damn smooth now I can't even feel the engine is on. This is what i expect the idle to be like on a new car but this being my 3rd 2.0T from the VAG family i know the idle is a little rough some times.

I put IKH24's in my car as a troubleshooting step earlier this week, due to a low RPM stutter I was getting and knowing I'd been about 15K miles on my stock plugs. They made a BIG difference in my car, much smoother idle when sitting at stoplights, and running a lot smoother under boost at lower RPM's as well. No noticeable difference in engine noise. In my case, this is likely a mix of stepping to a better plug as well as my original plugs just being weary after the ocean of extra power.

kinda smoothed out the car a bit, idles smoother as well.

Currently just swapped to Denso's IK20 like 2 months ago. They run pretty good. But now its mid summer over here and the car runs a little bit underpowered at those high temps.

At this point it's only showing symptoms after idling for 30 seconds or more (and even then not every time), like while waiting at a stop light. Only in first gear, second and beyond have no hesitation. This evening I swapped out the almost new Denso plugs (correct gap) and the problem seems absent.