The amount of HP an engine will put out over a given life cycle is a good point..... but with todays diesels running them with a modest chip, while being setup for it, will give far more trouble free miles than the rest of the truck can handle anyway. I'll take the piped and guage'd truck myself.
As far as the tranny...if that motor is BOMBED that 518 will never make it 140K under towing and a heavy foot. If it pulled as hard as Kid Jethro said, I'd bet he would be able to notice it acting up, if in fact it shot. BUt that is buying an used vehicle.....you don't know what the PO has done and you buy something knowing that things COULD be on their way out because it's USED.
As far as the tranny...if that motor is BOMBED that 518 will never make it 140K under towing and a heavy foot. If it pulled as hard as Kid Jethro said, I'd bet he would be able to notice it acting up, if in fact it shot. BUt that is buying an used vehicle.....you don't know what the PO has done and you buy something knowing that things COULD be on their way out because it's USED.


