quickaudi:STFA

Now, until I completely confirm the numbers, this is only what I have, but I'll present it and then ask for advice.

I'm stage 2, and after 40k miles on the stock NGK plugs from Audi, I swapped over to some iridium plugs. The plugs are Champion plugs that are stock for the RS6, so I'm not entirely sure that they are one range colder. Someone care to confirm? (Champion p/n 9201, seems to cross to a stock range plug, but can't get a confirm.)

With the stock plugs, gas mileage was high 25/low 26. With the iridium plugs at stock gap (whatever they came in the box), the best I've seen is about 25.5. Now, 95% of my driving is at 65 mph in 6th gear, so I'd expect to see the former, not the latter. (And, this data is across months, not 3 fillups and is quite consistent.)

My questions are: is this due to them being one range colder (if they indeed even are one range colder and not a "stock" range plug) or is it due to the gap? If it's the former, I'm going with Platins or another platinum plug in general, colder or whatever; if it's the latter, I'll gap them to something tighter.

Oh, and for the record, new plugs are a requirement in increased boost cars. 40k was waaaay too long for the stockers.

DAP@EPL

<img src="http://www.rpmoutlet.com/images/ngkheat2.jpg">

I'm significantly in the minority here (maybe I'm the only one) but I run cheap Autolite copper plugs (stock heat range) and change them with every oil change (5k miles).

-Dave Pramanik

Island Boy::Jeproks

OT: Dave, is Tony working today?

DAP@EPL

Yeah... he should be on the dyno (= can't hear the phone).

BeeRock::Riding Red

of course your more prone to detonation.
I dont know that it would work with a turbo car as well. doesnt the s4 like colder plugs?

eigenvector

im running those too