Change gear ratio on 454 class C
I've got 98 coachman class C 454 with 4:11 rears. I want to improve mileage by going to 3:23 gears. Will this work? Thanks
Forum Discussion
As mentioned, you will likely never save enough gas to justify the "upgrade"...that's assuming it works...which I suspect it won't with such an extreme jump.
Playing with gears used to work on pickups because they went from say 6000lb running empty to 14000lb towing heavy. A low numerical gear ratio would help MPG because it didn't take a lot of torque at the wheels to move an empty pickup so the new gear ratio allowed you to keep the RPM down in a more efficient range while not lugging the engine...Of course, you would wind struggling to hold 4th gear while towing but if 95% of miles were empty, it was a good trade off. (most actually would move in the opposite direction to a higher numerical gearing because they would be stuck in 3rd gear running too high of RPM while towing with the original low numerical gear ratio)
With a MH, you are always running heavy, so there isn't the same advantages to be had.
If you really want to pursue this anyway...you need to get the output curves for you motor and back calculate a rear end ratio that will put your motor at it's ideal RPM when cruising in top gear at your desired cruise speed.
Playing with gears used to work on pickups because they went from say 6000lb running empty to 14000lb towing heavy. A low numerical gear ratio would help MPG because it didn't take a lot of torque at the wheels to move an empty pickup so the new gear ratio allowed you to keep the RPM down in a more efficient range while not lugging the engine...Of course, you would wind struggling to hold 4th gear while towing but if 95% of miles were empty, it was a good trade off. (most actually would move in the opposite direction to a higher numerical gearing because they would be stuck in 3rd gear running too high of RPM while towing with the original low numerical gear ratio)
With a MH, you are always running heavy, so there isn't the same advantages to be had.
If you really want to pursue this anyway...you need to get the output curves for you motor and back calculate a rear end ratio that will put your motor at it's ideal RPM when cruising in top gear at your desired cruise speed.
