Mileage observations
We just returned from a 4000 mile road trip. Flatlands, hilly, mountains, wind - everything but rain! Over the coarse of 29 fuel stops and trying many different speeds, gears & rpms. I think I foun...
Forum Discussion
Yes, always OD will create more heat in the trans. When the output spins faster than the input on the trans there is a lot of stress on the gear, and why it makes heat, OD towing is not recommended unless you are going downhill or have a decent tailwind. But, this really depends on the ability of your particular trans.
Not true. When I had the 7.3 with a 4 speed and 4th being OD it ran cooler in OD than it did in 3rd. I towed every where in 4th. In 4th at 2000 RPM = 68 mph 2000 RPM was the sweet spot in that truck. I have no idea what the sweet spot is on my 6.7, havent had it long enough to fig that out. The truck had 250,000 miles on it when I sold it and the trans had never been touched other than change the fluid. Yes the EGT will be lower at a higher RPM but even with the chip I had it never got hot. 4" exhaust cooled it off 200 deg
Not true. When I had the 7.3 with a 4 speed and 4th being OD it ran cooler in OD than it did in 3rd. I towed every where in 4th. In 4th at 2000 RPM = 68 mph 2000 RPM was the sweet spot in that truck. I have no idea what the sweet spot is on my 6.7, havent had it long enough to fig that out. The truck had 250,000 miles on it when I sold it and the trans had never been touched other than change the fluid. Yes the EGT will be lower at a higher RPM but even with the chip I had it never got hot. 4" exhaust cooled it off 200 deg
