6 Speed

[mybmw28]

Any benefit to putting a 6 speed gear box in my 90 535i I am looking for better gas mileage.

[nrubenstein]

First you have to find one. They are very rare in big six bell housings. Off the top of my head, only certain E34 M5s had them.

[mybmw28]

But is there any benefit to it.

[ravenlord89]

Find out which transmission you want, then find out the gearing in said transmission, then do some research into what the best RPM and load your engine operates at, then compare all that data to your final drive and see if it would actually make a difference.

There is no yes or no answer here.

[nrubenstein]

Minimal.

Fundamentally, the M30 gets shit for gas mileage and you aren't going to change that with gearing.

[mybmw28]

Thank you