Join Date: Jan 2007
Location: Sacramento, CA USA 96814
FYI I've have a background in engine design by education, and I even briefly worked in the field before. My opinion of the Mototune method is that it's totally crap.
I think it's a fine way to quickly break in an engine that isn't going to last very long to begin with. If you race, and rebuild every few thousand miles, fine. Otherwise, you're probably going to turn a 100,000 mile engine into a 10,000 mile one.
Here's the thing - during the breakin period, two things are happening:
1. The parts are mating, polishing, and seating themselves. On the cylinder walls, if you do this too quickly, you eat right through the hone pattern.
2. The steel parts, and to some degree the aluminum parts are work hardening on the surface. This takes some time and if you eat through the very thin work hardened layer that forms, you're into metal that wears rapidly.
So do it slowly and you know you won't have any problems. Do it too quickly and it's a crapshoot. A few years ago GM had to recall and replace a couple dozen of it's Corvette ZR-1 engines all because one throttle happy factory delivery guy took it upon himself to "mototune" a bunch of new Corvettes right off the assembly line.