Ed,

Necessarily so. We're not talking about the capabilities of one engine compared to another. We're talking taking a specific engine and increasing the stress on it. All else being equal, more load = more wear. I'm sure a Jett will outlast most anything with the same power output. A Jett is better built of better materials than most other engines. That's why they cost so much. However, any engine run just fat of peak will last longer than when it is run on peak.