My car's DIC is currently saying that I average 36.2 mpg with mostly highway driving and little city driving. I drive about 25 miles everyday roundtrip. Today when I had an empty tank I had racked up about 265 miles on a full tank. Is there something wrong with the car?

2007 Cobalt SS/SC
Mods:
2.9 inch pulley
Injen Intake
Tune
Header
Siemens #50 injectors
ZZP heat exchanger

 

what are you expecting to get haha. 265 miles per tank sounds about right.

 

What I want to know is why the DIC is almost 18-20 mpg off? This tank of gas i stayed completely out of boost (almost), but the DIC is way off

 

when do you reset it?

 

Every time that I refill, the MPG usually shoots up to 36 immediately and just stays there the whole tank.

 

when your running aftermarket injectors the injector scaling changes, but the computer calculating mpgs doesbt know that. I thinks you are still on stock injectors. The dic is never right on mpg with aftermarket injectors.

 

^ ahh makes sense. the amount of fuel consumed based off demand and duty cycle for the stock injectors.

 

Absolutely 100% correct.

 

mpg is calculated off usec timing.

 

I'm confused, the computer calculator isn't right thought, its about 16 mpg off. When I calculate the mpg i get about 21-22 mpg but the DIC says I get 36-38mpg. So why would that mean im on stock injectors

 

The computer thinks you are stock, no matter what. Once you change the injectors, it won't be right.

 

Ahhhh I see what happened there, He forgot the "t" in it.

 

whoops, damn cell phone typing. Sorry for the confusion

 

Did that tune include an injector rescale?

 

Bump, lol?

 

How is this nws...

 

I think people use that because they literally only see the "!" in it.