Thread: Gear Ratio

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Back in the late 50's through the 60's the OEM "standard" seemed to be around 3000rpm at 70mph highway speed, but that was also when a 50,000 mile car was considered to be high mileage, and anything pushing 100,000 miles was reaching the end of it's life expectancy, right? I'd much rather be cruising in the 2000 to 2500rpm range myself. Much less wear & tear on the engine, and closer to the efficiency point on most.

I'm using 3.25 gears, 29.1" tires and am turning 23-2400 rpm at 65 mph with a 1:1 ratio C-4 transmission. If I decide that I want to put the 3.79 gears back in, that same rpm will be about 55 miles per hour or about 10 mph less for the same wear and tear. It all has to do with economics - that is, your wallet, gas mileage and what your earlier engine wear will cost.