I bought my N/A S4 last fall, great gas mileage the whole time...
 

I always read these horror stories about how people are getting 8-12 miles per gallon and stuff

Whenever I get gas, I write the miles on the trip counter down on the receipt and reset it. every month I have been getting 19-21 miles per gallon, with some red lining. There was one week where I got 16 mpg, but I was probably driving real hard that week.

I was wondering, if I'm getting that kind of gas mileage stock, what if I tuned the fuel curves? How much could the gas mileage increase?

Also, I did the water trick with 150,000 miles, and damn, the car runs so unbelievably smooth now. I can't wait to restore my fc, and maybe turbo it :cool:

In my escort, I always coast down hills(car in neutral) and even turn the engine off when it is a decent downgrade. I also dont usually get up the the speed limit... keep it under 2k rpms in 5th. I get insane gas milage, I also shift under 2k when getting up to fifth and cruise ar 40 (1.5k rpms(just enough so I can accelerate if I need to but still get good gas milage)) I do redline it once a day though. Funny thing is when I do the water trick on my car the water dosent get in the engine right away, I need to get past 3krpm for the water to get in there and it makes a nice steam cloud, must be putting it in a wrong tube or something.
I would think you would need a standalone ems to tune the curves.

Whats the Water trick?

Would you need a full standalone or would and safc be good enough?

???

Water trick..... Many people have had good experiences with this, a few have had VERY bad experiences with this. Everyone should read up on this and be very aware of the pros and possible cons before they do this.

LOL... Me too!!!

Yeah, I know you need a standalone or a s-afc for tuning the fuel curves...

For the water trick, I popped a vacuum hose off the intake manifold. I got another long hose and attached it to it, and dropped the hose in a gallon of distilled water, and revved the engine to 3k-4k. went through 2gallons, andt he car is so smooth now.

Gotenks
you said the water trick helped a lot, everyone seems to put the water in useing different vacum lines, since yours worked well, how much water did you use, what vacume line, and at what rpm. Pretty much tell me how you did it pleez

Alright, on top of the manifold, you will see 3 vacuum lines. 2 are about the same size, and then there is one that is a bit bigger. I used the hose that is a bit bigger. I bought 3 gallons of distilled water, but only ran 2 through it. I didnt do the third, because I drove it around after finishing the second gallon, and it was real smooth, so I didnt want to over-do anything.

Most of the time I held it at 3000 rpm, and sometimes all the way to 4000 rpm.

i also did the water thing, did not notice that big of a difference but still a little

19/24MPG. I saw gains when I installed a performance catalytic converter & partial headers.

As long as you don't re-tune for power you'll get better fuel economy with intake & exhaust.