HELP

[NRG-GT]

so my only mods are off road x, and 4.10 gears and i got a custom tune for 93 octane. I am happy with the gain in take off from everything, but after i installed the tune which was last my gas mileage went down to 9 mpg before the tune i was gettin around 20......... any suggestions on whats going on?

 

[mac10chap]

running extremely rich??? check your exhaust tips and see if they are turning black...

either that, or just get your foot off the gas pedal...full throttle + full time = 9mpg

 

[Lee's05GT]

i cant remember if it happens when you load a tune up but doesnt the ecu re-figure the gas mileage once you do something to it? I know it does it if you get a CAI put on and it takes a while to figure your gas mileage out after you drive around for a while.

 

[jroc07gt]

i can switch between tunes all day and still show the same mpg

 

[blk281gt]

Wow, that cant be right, Try reflashing the computer (install the same tune again) . If that does not work, call the person that you got the tune from. You should get 15 mpg avg at the very minimum with 4.10's.

 

[dysan]

I would suggest disconnecting your battery for 15-30 minutes. Then once you re-connect there's a fuel trim re-learn procedure to go through. I believe it's in the manual. Something like starting the car, idling it until it reaches operating temp, then turn on the a/c and let it idle for another minute with that on. Then keeping the a/c on, drive the car for 10-20 minutes. See if that helps.

 

[EagleStroker]

Is that your actual gas mileage (checking mileage vs fuel) or just what the computer says?

 

[TonyN]

Is your speedometer calibrated to the 4.10's in the tune?

 

[NRG-GT]

its the actual gas milage the car is saying i am gettin 19 but im not i have drivin 35 miles and already used a quarter tank!!!!!!! and yes the tune included my gears

 

[TonyN]

I think you should just drive it and let it learn it's parameters/tables. You may even want to disconnect the battery for an hour or so and then go drive it. MPG may get better after a hundred miles (once the drive cycles are completed).

If not, your tune must be out of whack and running rich, basically wasting fuel. How does the car drive? Feel strong?

Also calculate a whole tank of fuel and not just a 1/4. Gauges are not 100% accurate and who's to say you used exactly 1/4 tank.

 

[EagleStroker]

Also calculate a whole tank of fuel and not just a 1/4. Gauges are not 100% accurate and who's to say you used exactly 1/4 tank.

^ Exactly. Don't trust our gauges, top the car off, drive 200 miles and top it off again. Then divide the number of miles by the gallons used.

 

[jroc07gt]

i say disconnect then reconnect the battery. then reload the tune but check to make sure that the correct gears and tire size is selected in the options.

 

[NRG-GT]

i have run 3 tanks of gas through it and checked the milage every time i just said 35 miles at a quarter tank to give yall an idea of how bad it is. but any way i will try reloading the tune and dissconecting the battery as well thanks guys

 

[jroc07gt]

i have run 3 tanks of gas through it and checked the milage every time i just said 35 miles at a quarter tank to give yall an idea of how bad it is. but any way i will try reloading the tune and dissconecting the battery as well thanks guys

what the on board says is affected by what gears and tire revs are set in the computer vs what you really have. i have nittos and the nitto site says they are 810 revs per mile. i have changed my tune from 785 to 810 and there was a noticeable difference in what the on board said.