calculator may help you in your quest for the "Perfect Rear End Ratio"
We are not responsible for any potential errors. Always verify calculations
before making changes and driving your vehicle! *Engine
RPM should be measured in direct drive, this is usually the highest non-overdrive
gear. In automatics with non-lock-up torque convertors, convertor slippage
will result in additional errors, this can be minimized by measuring the
RPM during light cruise to near coast conditions.