Mpg chips.

[atreis]

Assuming a reasonably new vehicle: Given all of the pressure the manufacturers are under to improve fuel mileage on vehicles of all types, if these chips/tuning changes worked without undesirable side effects they'd have already done it.

The best, proven, and free way to improve your mileage: Slow down.

[Jimbo56]

Slow down is right. I was passed yesterday on I40 going into Asheville by a SRW F250 pulling a 3 axle toy hauler going at least 80 mph. Not just fuel economy. But overload, over speed blowout waiting to happen.

[wbob]

Anyone using one of the programming devices for the Mercedes V6?

[B17drvr]

It’s not really a chip. It is a tune that you download. SCT, 5 Star, banks, and Bully Dog are tuners that provide the download.

[sportcoupe]

There haven't been user replaceable chips for vehicles engine programming since OBD-II (1980's). I used to make them.

Todays modern engine controllers are smart and locked down. There are piggyback devices that you can install or you can ship your computer for unlock and programming.

Aftermarket programming is about getting the most power you can, usually. This means running premium fuel all the time. MPG is of no concern.

Buying a programmer to increase your heavy RV mpg is a pipe dream. Driving slower and accelerating gently will provide more increase then any programmer ever can. Mind your braking as well, coast earlier rather then brake when approaching traffic.

[knucklehead]

Originally Posted by Beau388

Ford and most other RV engine manufactures have not had replaceable chips in the ECU for some time. Modern ECUs can be reprogrammed by using a "tuner" .

To answer your question, no there is little to no increase in fuel mileage to be obtained by reprogramming the ECU. Most RV get their best fuel mileage at 45 mph as wind resistance and rolling resistance increase significantly above that speed. Reducing your traveling weight can also increase your fuel mileage.
What a ECU programmer can do is make the throttle more direct (increase sensitivity), significantly change the shift points in the transmission and increase the HP at WOT slightly. All of the items will likely DECREASE fuel mileage, but the coach will be infinitely more enjoyable to drive (NMHO).
The forgoing applies to atmospheric intake engines. Turbo charged or supercharged engine can often see fuel mileage and torque improvements by reprogramming the ECU.

45 MPH seems very slow?? I would think 55 would be best and not piss off evryone on the road!! I have a Scan Gauge and I did a test going to the NC beach from the piedmont, so the road was very flat. 63 was the best MPH that I saw that gave me the best but I'd bet 55 would be better!!! I don't know why, it's just a hunch?? Bob