A few years back I used to run some truck-mounted soils drills. Most were gas powered, 4 cyl Ford Industrial and 6 cyl 3000 cid Ford Intrustrial. You basically ran the engine a little above idle and let the torque do all the work. NOT SO DETROITS--The one rig I had that was powered by a Detroit needed to run WOT to develop its power. Eight hours of listening to that screaming and I was ready to forget diesels forever. Thankfully, I found that not all diesels are like Detroits.