Over Drive
I have always wondered if I put an overdrive unit on my RV will do any good. If it gives you a 10% decrease in RMPs does it give you 10% better gas mileage? Or just 2 or 3% better MPGs. Would it be wo...
Forum Discussion
Buster...it appears that I am the only one so far that has actually added an under/overdrive. Several years ago, I did this on a 1988 33' motorhome with a 460 Ford.
Before the overdrive was added, the engine was turning 3000 rpm at 60 mph. With the overdrive, I was able to cruise at 65 mph at about 2600 rpm.
Another benefit of the U/OD, is that I could split gears and have a 1st over, and 2nd over too. That was a great advantage going up hills where 2nd was to low, and 3rd was to high.
I'm pretty sure that I didn't recoup my cost in gas mileage, although I did get a couple of mpg better because of the lower rpm when cruising. The main reason that I bought the unit was because of less wear and tear on the engine running at lower rpm's, and I could cruise at higher speed limits and not have the engine roaring.
Before the overdrive was added, the engine was turning 3000 rpm at 60 mph. With the overdrive, I was able to cruise at 65 mph at about 2600 rpm.
Another benefit of the U/OD, is that I could split gears and have a 1st over, and 2nd over too. That was a great advantage going up hills where 2nd was to low, and 3rd was to high.
I'm pretty sure that I didn't recoup my cost in gas mileage, although I did get a couple of mpg better because of the lower rpm when cruising. The main reason that I bought the unit was because of less wear and tear on the engine running at lower rpm's, and I could cruise at higher speed limits and not have the engine roaring.
