Cenpeco Atomic power in my 2002 7.3 with 220k miles. The only engine maintenance that I have done was replace some glow plugs and the CPS sensor. I have 410 gears in my dana 60s, with a gear vendor over drive, and get around 12 in town, and 14 on the highway.
I do use Archoil in the fuel but until I made about 90K on the engine, I used fords cetane booster. The Archoil works well with my espar. My main concern was keeping the EGR as clean as possible and it seems to be doing its job as compared to the Ford product. On the other hand I did see an improvement using the Archoil oil additive.
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2006 Ford 6.0PSD EB-50/E-PH SMB 4X4 Rock Crawler Trailer
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"understeer is when you hit the wall with the front of your car, oversteer is when you hit the wall with the rear of your car, horsepower is how hard your car hits the wall, and torque is how far your car moves the wall."