Ok, so I took my new used truck in to the dealership and had the ECM flashed. I had a feeling the PO had a tuner on it and failed to reset it before selling it, resulting in the poor mileage I have been getting.


Driving the 30 miles from Topeka to the house, I have averaged 13.2 mpg consistently since I got the truck.. after having the ECM flashed and reset to factory, I am getting just shy of 18 mpg making the same trip!
Much happier with that..

What I was told was that there was no evidence of a tuner having been used on the truck, but that the factory settings were "out-dated" and that an up-dated program for the 04.5 trucks was issued in 2007..
They updated mine,and its made a huge difference..

 

The ECM keeps a count on how many times it has been flashed or updated. Usually a high number indicates a tuner has been used.

 

You can do better. The truck's best speed for mileage is 50-55 mph. If you also run a tuner, even at a minimum setting will give at least 1 to mpg more. (They advance the injection event). Pay attention to tire pressure. 55PSI in front 45PSI in back. I get 20-21 mpg if I drive carefully.

 

You can get away with 55mph in Germany? They have higher quality diesel if I'm correct.

 

Nur im Stau.

 

If you are just going by the overhead that doesn't mean a thing. Each flash effects how its computes and displays mileage.

The only true way to tell is with hand calculations after each tank.

 

This ^^^^^^^^

When I had a flash it affected my overhead for the worst. It went from being a .5mpg off to over 3-4 mpg off. When I changed out my cam doing mileage runs to compare, I was reading 23.4mpg on the overhead. I was actually getting 19.6mpg. Hand calculated filling the truck up to the top of the neck. I was only getting around 18.4 mpg before the cam swap.

 

OK, initially I was going by the OH, but was aware it might be off..

After 264.3 miles, I refilled the tank with 15.35 gallons of fuel.. works at to just about 17.2 mpg.. OH was reading 17.1..

Im still happier with it than I was..