Answer to "Caterpillar C-15 ACERT ECM Tuning Options"I have a 2007 379 pre emission nxs and all that hardware changing is a bunch of crapola. Sorry to say you are wrong. You can throw every spec my way but my truck was a 475 and my mechanic and I turned it up to the 625hp 2050 torque and played with the fls fts numbers. It’s a pullin ##&&% hands down. Never changed one hard part. I got a couple buddies with older 3406e with the 601hp 2050 torque and on the hills there’s no comparison. They usually hit a speed they can hold and mine just keeps building power and speed going up. It is amazing what this engine is capable of. I also went from 4.5 mpg to 6.5mpg. But once you lay into her hard mpg’s are nothing to record. I never take her over 1500 rpm, and run about 70 on Highway. She gets to speed quick and drives to my likings without going over 1500rpm. In fact there’s not a truck in my area that pulls like mine does. I’ve got 75000 miles on so far from when I turned her up and she don’t burn oil and runs like a top with 1,350,000 miles.