gk1

I decided to change my spark plugs on my 2012 S-Tronic S4 and it is surprising to see the variety of plug heat ranges recommended by various websites.

Denso lists IK16 for a 2010 on their website...(only year listed) and sparkplugs.com lists IK24 for the 2012...did the engine change that much in 2 years that they now recommend a plug 3 steps colder?
Bosch's show up in the range of 5-8 which is close to Denso's range but also is a broad spectrum.
No official NGK replacement listed although NGK is OE (on my car anyway).

After some searching I ordered what I thought were OE plugs but received the Bosch FR5KPP332S after questioning this I was assured they were OE replacements. I put them in and they worked fine...or seemed to..I noticed when pushing the card hard in D up-shifts would occasionally happen early 6400 RPM or bounce off the rev limiter. Neither of these things happened before...earliest would be around 6800 and never bounced off the limiter. (Only thing changed was the plugs.) I also noticed cruising in 7th and giving light to medium throttle resulted in a bit deeper exhaust sound than previously. Odd I know, but I now switched back to OE plugs from the dealer which are NGK Audi P/N 101905611G and both the deeper sound and strange shifting characteristics have stopped.

Only thing I can say by way of inspection is the tip looks fine (no damage or fouling) and the gap on the Bosch was .028 vs. the NGK .032. The ceramic nose does appear quite different between the two with the Bosch being very long taper (hot plug) and the NGK visibly shorter (cold plug). I wish I knew the exact heat range number for the OE part but since it has an Audi P/N it does not correlate to NGK's numbering. I'm wondering if it correlates to an NGK 5 (hot) or 8 (cold). Or are the OE plugs specialty plugs that do not equate to an exact aftermarket replacement...just ones which are "close enough"?

Anyway, thought people might like to know my experiences.

Jones2012S4

The OEMs are NGK 8, only way I could find them was through OEM Audi parts resellers and they were not cheap.

I am highly modified so for summer I run the NGK 9's and have had no issues.

gk1

NGK 8 matches the Denso IK24 which means the Bosch 5 was 1 step hotter! Booo. Oh well...live and learn.

RUM4MO

In the past, I've normally found that you could find the NGK details near the top of the metal part - round the outer surface. It seems to be a bit early in the life of these long-life plugs for these engines to find NGK outlets selling them.

gk1

Just the Audi part number on the plug metal... 101905611G R1 JAPAN. On the hexagonal part there is an M14W stamped but figure that has more to do with it being a 14mm thread.

RUM4MO

Oh, that is not fair! I'll need to check the last plugs I took out of my old B5 4Motion and report back, maybe VAG has stopped its plug suppliers from including their own identification just in case you buy NGK plugs elsewhere.

RUM4MO

I've checked some factory fitted original plugs, and they have both the NGK part number and the VAG part number stamped round the ring above the crush washer seal, so at one time VAG sourced NGK plugs did carry both reference number.