Yes I let it warm up, but usually not that long; only about a minute or so before actually moving. I do, however, drive really slow and shift early (at or around 2k RPM) for the first 10 min or so, or until the engine is at full temp. I absolutely never get into boost until its warm or very close to it though.

Damn... I might as well do some plug wires if it's gonna be a process. Well, I just read a pretty intertersting thread from Sparkplugs.com about fine wire Iridiums (granted he is a sales man, but the science is legit) so I might go that route:

https://www.audiforums.com/m_404296/tm.htm

Furthermore, the DENSO Iridiums seem to be priced the same as the NGK Double-Platinums (I know they're both overkill longevity-wise, but I happen to believe in the performance/economy gains with precious-metal iginition components - how can you not?):

http://www.sparkplugs.com/results_ap...p;AAIA=1368233

 

Your car actually has a coil on plug setup which puts a coil and spark plug boot right on the plug, leaving you withno wires too change so you won't have to worry about that. Have you checked your air filter lately? A dirty air filter or a racoon or something in your air intake will cause some poor economy. Other then that someone with a scan tool could take a look at your sensor data and check to make sure everything is running within its parameters.

 

Yeah, DUHHH. I should've know they've got the coil packs in each plug wire (just like the VW's)...[sm=sorry.gif]

Well I had both AutoZone and the Dealer run their scanner's, and they got nothing but the faulty CTS code. I bet that's what it is, but I'll def. check the filter, MAF and plugs anyways.I justhope it's not the engine mounts or something, but I doubt it considering the mileage.

 

wow, glad i got this car! my other car got around 8mpg [:@]Any 5 minute drive to somewhere and back home seemed like it was 1/4 tank

damn 60lb injectors and 520hp

 

Not quite my territory (I have a lowly A4 1.8), but I usually only get 180-200mpt. Probably because I am almost always flooring it... Still better mileage than my 302 4-barrel.

 

I seem to get about 19-21 mpg around town and about 25-28 mpg on the freeway. I think if you are getting under 200 miles to a tank, there is something wrong with your car. I know a lot of other cars run very rich and get horrible mileage when the O2 sensor goes but usually that will give you a CEL.

 

I usually see around 230-250 per tank, but my foot is usually always in the throttle once its warm, seriously how can you resist. Still costs less to drive than my 4-by-Sonoma did, and is just a bit more than my jetta. NGK is OEM equipment for the S4, around 12 beans a plug, suck it up and do it, its not bad. Just make sure the engine is cool before you take them out of the heads, helicoils suck.

 

So if the DENSO Iridiums are about the same, would you still opt for the OEM NGK's (which I think are Platinum)? Has anybody tried or is currently running these plugs? Is there a DIY on the plugs, or is it pretty straight forward?