I'm retired from the trucking industry and I was behind the wheel of CAT engines most of my 44 years. 1.2 million miles was the furthest I drove one engine before a rebuilt. And 750,000 was the least amount of miles before a rebuild. This past spring I had my Workhorse in Joe's RV Lake Havasu City, AZ. (Workhorse dealer in L.H.C.) and one of the mechanics was working on a DP with a CAT engine. I quipped nice engine and he replied back to me, all the CAT's are nice except the 330 H.P. I didn't ask any other questions as I was leaving but he told me they work on a lot of 330 H.P. CAT's in that shop.