Perhaps on the 617 engine the crank indicator is harder to read, but on the OM60x engines it's quite accurate. I used the dial gauge method and compared to the crank indicator, and it was DEAD on (within half degree) every time. Plenty close enough for a rough check, although you can do the dial gauge too if you want to confirm. Again, I have not attempted this on a 617 engine, but you piqued my curiosity with your findings! I wonder if that's why my 123 has poor fuel economy...? Hmmm!
