[s-cars] Ideas to Increase mpg?

[David Kase]

I did a 7 month search in the archives and did not see a thread related to fuel mileage.

I am keeping my B5 S4 as a secondary car and am currently doing some upgrades to it.  My recently purchased S6 is doing dd duty.  I have a 60 mile round trip each day and at 20 mpg, I could stand better fuel mileage.  I do 55 of the 60 miles on the open highway.

I was thinking of selling the C4 and buying a TDI (saving ~$100/month) but I just don't think I will enjoying driving it everyday (Probably a 99-02 Jetta).  I also am considering a 1.8T A4.  But, I figure if I can get the mileage better in the S6 then I will just keep it.  I'd love to get over 25 mpg but I don't know if it is even possible.

Step 1 - go from CRAP (TAP) ECU to stock.  Then what?  

No matter what I do I know I will be rolling on the power from time to time.  It seems like you can never get that mileage back over a tankful.

Respectfully,
Kase