The DT360 was a joke of an engine. That's what they've got in one of the county-owned rescue trucks. It stays on the floor all the time. That's not a problem with I6 vs. V8. That's just a problem of not enough engine for the truck. You need a 466 in a truck that big. I read somewhere that when Ford came out with the diesels back in the day, they wanted a diesel that drove like a big block gas, so they got a big displacement V8. Dodge wanted a diesel that drove like a big rig, so they put a powerful, fuel efficient I6 in the trucks.