I just bought a used 1999 LS and my gas light is coming on at about 260 miles. I drive on the freeway mostly, but sometimes theres a lot of traffic. Can people indicate what type of mileage they are getting? The car has rims, AEM CAI, and DC sports headers. Have people seen their mileage drop due to these mods?

 

92 RS here with 288K miles and I, H, E, resonated test pipe, and fresh ignition components. I hit 300 miles usually when the light starts to come on, and if I push it, I get 50 more befor I fill it back up. This is on a mix of Hwy and city driving.

When I track my mileage, I average 30-33 mpg, unless it is mid summer and I run the air fulltime, then it can drop as low as 28. Driving style has a big role in mileage also. Unless I have a hair up my ***, I usually accelerate gradually and coast to red lights instead of hauling *** to it, then slamming the brakes.

There are many threads on this topic of mileage, thats probably why no one has bothered with this thread. Oh, and most bolt-ons will usually help mileage if you can resist the temptation to drive harder because of them, ie. the sound of the intake at full throttle, etc.