(All said In My Humble Opinion). I like the 6.2. The design of the HMMWV is what it is. It was designed not to outrace the rest military. It is a High Mobility Multipurpose Wheeled Vehicle not a Fast Attack Vehicle. The 6.2 fit very well with the overall design of the HMMWV. The HMMWV was designed with cold war parameters. In our more modern times it seems strange to many why they designed the HMMWV the way they did. They picked a vehicle that could go almost everywhere military cheap (you could do things similar cheaper) that had great success using US parts. I think it is a great vehicle. I think the 6.2 is a great engine. The 6.5 is a 6.2 with some upgrades. Also most 6.5's are detuned so they are very similar.
Is an Apple phone so superior to a Samsung. Yet people will say to me Apple phones are the only phone everything else they say sucks. But, more people actually use Samsung world wide, so it works.
If you take good care of any engine and have the know how you can get many 100's of thousands of miles out of them. Not un-conceivable you could do well over a million. Maintain, maintain.
There is nothing wrong with a 6.2.
The biggest issue with a HMMWV is the transmission. The 3L80 is by design limiting, (speed, gas mileage, and to some degree power). But that is by design. They wanted an automatic transmission without sophisticated electrics that would work after Nuke day, they did not want service men (who are normally young stupid men) driving too fast, they wanted it to go through and over almost anything.
The 6.2 and the 3L80 was chosen by design. And I still love it.
Good luck to you.
