4th gen trucks are great and all, but the old VE and P-pump 12V trucks Even the VP44 trucks and early (03-06) common rail trucks seem to get better fuel economy.

If I gingerly drove my '02 truck, maintained 62mph on the freeway, let everyone pass me and rarely hit the brakes, I could get 20mpg out of it. Pretty Damn impressive it you ask me! Especially for a 4x4 Auto truck. I wouldn't believe it unless I had done it myself.

Friends of mine have reported similar results from various models of 2nd Gen trucks and another friend of mine reported 20mpg from his '03 dually w/ manual.

I doubt I'll ever get the 20mpgs that I used to, and quite frankly, that was an anomaly. Realistically driving the speed limit or faster, I'd get 16mpg.

The 4th Gen trucks have a weight penalty, because they're bigger. Plus, the engine is bigger. But you'd think with the emissions system taken out of the equation, better fuel injection technology, VGTs and 6-speed transmissions. I think I ought to get the 16mpg I used to. Not the 14 that I typically get on the HWY.

Logically, it makes sense that if you tune the truck like a 12V, you might get performance, including mpgs, like a 12V. Is there any truth to that?

If I eliminate the pre-injection and post injection and well as bump up the timing, that saves fuel right? Is it significant?

Any tips on making a good 12V tune?

TIA!