Hi all, I've only been getting 25mpg on my 2008 fit w/ 19,000 miles on it....my wifes 2009 Fit get's 33mpg on the same roads! I can't figure out the problem....tire pressure is good, clean air filter, fresh oil, easy driving. There are some hills that I drive through but it shouldn't knock 10mpg off my car! At least I hope not anyways. I bought a OBDII scanner and am wondering if there is something I can do with it to improve the gas mileage. There are no signs of trouble but it does allow me to read live data. What should I look for as an indicator of the poor gas mileage problem? thanks!!!

 

You need a scan gauge or ultra gauge, both would work in either car. It would give you real time readings and you would see how your driving. Take it out on the highway for a ride and do a few full throttle passes and let off the pedal and coast down. You dont need to speed but releasing the pedal seems to help set the perimeters. OBD2 scanner just erases codes unless its a professional one where you can run it and play back. See where the engine loads are and fuel trims.

 

Can you switch cars for a while and see if it's the driver/roads or the car?

 

Yes, it plugs into the OBDII port. You have to reset up the engine size and tank size.

ScanGauge - Trip Computer + Digitial Gauges + ScanTools

UltraGauge Automotive Information Center and OBDII Scan Tool

Both will tell you mpg.