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Old 06-12-2011, 02:36 PM   #7 (permalink)
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Originally Posted by slowmover View Post
The 6.2 and 6.5 were not so hot as tow vehicle engines either. I'd spec the trailer QUITE carefully.
Nah, they were just fine, but remember they like to tow slow and steady. They will tow fast and hard just fine too, just like a 350 but then you have to be rebuilding the darn things every 100k or better.

My 120hp 82 c code diesel went the last 100,000 miles half of which was towing 10k+ of two enclosed trailers (one camper and one enclosed trailer). Much of which was right to the floorboards getting 10mpg going 55mph until we found an air deflector raised the top end to 65mph/12mpg (all with a turbo 400 3 sp). The first 100k I couldn't speak for.

It was slow & underpowered but I could make it up any hill and thing is still on the road today.

A few things to remember, the best longest lasting 6.2/6.5 rigs are the ones with the least HP and the best set of gears. (and pure luck) The weak spots are the crank and harmonic balancer with older units suffering from bad heads and bad bottom end webbing.

If I were setting up a 6.5 as a tow rig, I would up the compression (different precups/heads), turn down the IP a good amount, lower boost, advance timing and make sure to have both an oil and a xmsn cooler and play it nice on the throttle. In my case I would never own a GM diesel without an MT and you will learn why if you use one for any extended period with an auto.

There is still a guy in TN that uses old 5.7DX's to tow lots of weight because they get better FE than more capable rigs, as with anything if you put a good set of gears and a set of guages in the right places, you can do almost anything you want with any motor but you have to watch it to make sure they don't fall apart from abuse.

If your the boost it and floor it all day type of guy a 6.2/6.5 is definately not for you unless you detune the thing to the point of being incapable of grenading.

Like I said originally the only reason to have a 6.2 is for FE and occasional towing. They tow slow but will get you where you want every time so long as you use COMMON SENSE.

They were not designed to be a cummins and you shouldn't try to use one as such. They are more like a VW 1.9 diesel that gets better FE and can haul something.

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