Looking for some friendly advice

Fuel economy readout from ecm is inaccurate at best. Detroits for some reason are really bad. verify odometer is correct then use manual calculation. Ive read your prior posts and wonder if you really need the power with what your doing. Ive owned 3 Centurys, their good trucks.

 

I own a 2000 Century with a cat c-15 and most of the loads I pull are around 10000 lbs. I drive in the upper left coast region, and most of the time my speed is around 55 mph. My 13 week average is 9.51 mpg. I did not get that kind of mileage until I had the engine rebuilt and turned up to 500 hp. I have done a lot more than just rebuild and turn up the engine. I added centramatic wheel balancers (about 3% gain), AirTabs (about 4% gain), and went to super singles on the drives (saved about 400 llbs, and now after two years MIGHT be seeing a gain).

Your MPG is really impressive, leave it the **** alone!!

PaulE is right about checking ecm against the pump mileage. It's not just that the ecm can be inaccurate, a change in the ecm mpg can be a signal that an injector is going out.

At 1.2 million miles, my Century is suffering from various electrical wiring harness failures. Look especially at the harnesses from the headlights. The harness can get crimped from the hood closing on it and slowing getting chewed open.

Ken