NAC Diesel Chevettes had an Isuzu diesel engine. Diesel from the ground up. Not some thrown together gas/diesel. I had the same engine in my Isuzu 4dr sedan. Got 40 mpg city and Hyw. The best I got was 54 mpg on a trip to Yellowstone and Cody,Wy. When I finally quit driving it, it had 275K, original clutch, but ate startermotors every 90K. Al