Anyone else having issues with the fuel computer/message center?

It is saying I'm getting really good milage (28-36)...

Problem is, after a tank of gas, it says I've only used like 10 gallons, not the 15 that I have really used.

Any ideas?

Thanks in advance,
Brad

 

Let me get this right first: your comp shows 28-36 mpg WITH a supercharger? Definitely not possible, no matter how you drive it!
The tank capacity issue might give you a clue as to what is really wrong there. Have your dealer check it.

 

Thanks for the reply.

Let me clarify. I didnt have this issue before the blower. Also, I removed the blower for a while and the N/A tune was correct (both JLT and stock).

So now I have installed the blower again with an updated SCT tune, and I have the same problem.

The problem/issue has to be in the tune.

 

Does the speedometer read correctly? If not, the tune may have a different gear ratio set in it, and it's making the car "think" it's going more miles than it really is.

 

I will check that tonight, but Im pretty sure its correct.

Thanks,
Brad

 

O,

Even if the gear size was different, the Gallons Used is off as well.

 

did you change the pump?

 

No sir, the pump is stock.

I was thinking that the fuel used was calculated by the flow across the injectors. If the car had bigger injectors than it thought, than it would show that it had used less fuel. But...

1. I dont know if that is how its calculated, and

2. The program is set for 39lb (stock Cobra injectors) which it has.

Thanks,
Brad