My Jeep was reflashed for the '07-'08 transmission overheating issue adding the "HOTOIL' warning. Two tanks of gas later, my mileage seems to magically improved? Is it possible that the refash reprogramed something else that could contribute to this???

 

Is this measured or using the internal computer?

 

Do they change the seasonal gas formula in your area?

 

This is very possible. During the summer I can get 25 - 26 mpg on the highway with the 3.21 gears and 6-speed and 32" tires (engine is only turning at 2000 RPM at 70 mph). During the winter here I get 23 mpg or so on the highway. So for me I see about a 3 mpg drop with the colder weather gas.

 

Calculated by miles drive / gallons.

 

California. Same slop all year round.

 

I swear I've noticed the same phenominon on mine as well...

 

I believe it has to do with the reset of your computer with the reflash. When I return my Hypertech programming to stock for trips to the dealer, it starts at 18 mpg or so and then counts down to a more realistic number.