120 Tune read 25% less fuel used than actual giving overly high MPG readings.

I have run the 65 HP tune on my 2007 LBZ for about 6 weeks straight now. I fill up at the same pump every time and always fill all the way up to the filler neck,waiting on all foam to dissipate. On the 65 HP tune in my ...

I am currently running the 120 tune and it definitely screws up the DIC fuel meter. It appears to show about 25% less fuel used than actual. I will fill up here in a day or so and verify. This of course shows a 25% error in MPG.

I've also noticed that to correct the Speedometer & odometer I have to ...

These readouts are nototiously inaccurate with performance tunes, best bet is to log actual mileage vs fuel used and do the math manually.


Strange. I run my 2007 LBZ on the 65 tune and the fuel used indicator is within 1% of actual.
The last two tanks were:
used display= 22.5 gallons pumped ...