The Fleetwood Flair is a 26 foot motor home. I was getting 11.8 mpg with a bad O2 sensor. I have replaced that with new. I have gotten lower mileage because of a trip towing a toad. I got 9mpg with that combo.
I have installed an MPGuino fuel mileage meter. I'm in the process of calibration.
I have calibrated it. The trial and error that I did to get it to read was very close. It's neat to actually
stumble on the parameters that work so well the error was almost negligible.
I set Micro/sec/gal at 108507850 to start. Too low, I drove around in a large parking lot. Must have looked silly going in circles! I guessed at 90000000 and that was too high. reset it to 70000000, still too high. Reset it to 40000000. Just right. I set the VSSPulses/Mile to 8000 from ECM to speedo signal.
The VSSPulses/Mile calibrated to 7848, so 8000 was real close. The MicroSec/Gallon came out to 36746215 very close to the 40000000 number i set at first.
Now I'll have to verify it on a long trip.
Anyway 3.58 gallons for 44.56 miles = 12.44 mpg.
Not bad for a 14000 Lb vehicle.
The MPGuino said 14.4 mpg on instant. Very stable.
I installed a JCar module to square up the injector pulses. It works well. I still haven't gotten a good calibration so I'm still relying on actual fuel up numbers.