I cleaned out my throttle body, cleaned my mass air flow, changed to synthetic diff fluid & installed a z-tube & I'm very pleased with my gas mileage.

 

^^ everythin is clean, i just changed my oil to synthetic, i have a ztube... same mileage.

 

With intake and exhaust your MPG went up? That makes no sense. Maybe you meant the other way, from 14-15 it became 12.

 

I have an X and I am only getting about 16-18 mpg. Mostly highway. Sucks but what can you do?

 

My mileage is better after the MODS! And as far as I know, it is supposed to be better. Honestly, I was expecting to be A LOT better... but it is not! It's just a little better. WEll, car is faster now... that's all it matters!

 

All Stock sedan... Just filled up this morning... 23.8mpg. Auto 03.5, 260hp. Commuting to work... so 30% local and 70% hwy... (but as you guys from LA know... freeway in LA at rush hr. is pretty much stop and go.)

 

I just switched out the stock 17" RSA's for Bridgestone Potenza RE960AS Pole Position (235-50-17). The specs at Tire Rack show the revs per mile for the RSA's as 797 and the Bridgestone as 792. My milage has gone down. I know new tires will do that. I now have 1000 miles on the new tires.

Do the different tire sizes also affect MPG, as well as the readings on the speedometer? By having less revolutions per mile is that making the speedometer read lower and thus make it seem I travelled less, and got less miles out of the same tank of gas?

 

The revolution increase in very minimal and won't impact anything. The reason your MPGs went down with the new tires is because of the increased drag from the wider tires. The tires are probably heavier too which is the worst weight you can add to a car (rotational weight).

 

I can't wait to get 19's with a 265 in the back... then I should see 8mpg.

 

dooooooooooood

im gettin whored at the pump

i have suspension issues tho ... gona take it in to dealer. u thnk it can be part of the prob?