bmwteaser

Very normal. BTW, 5th gear is sorta your OD.

Jeff Lange

iTrader: (1)

This is an old thread, but overdrive as a concept doesn't really matter at all because you need to include the final drive. A non-overdrive transmission with a 1.0:1 gear and a 3.2:1 final drive is the same gearing as an overdrive transmission with a 0.75:1 gear and a 4.3:1 final drive.

The W55 in the US-spec IS300 has a 5th gear ratio of 0.85:1 and a final drive ratio of 3.727:1 with a tire size of 24.6 in. This works out to 79 MPH at 3400 rpm, as the original poster was seeing.

Jeff