Re: Do you know how fast your 8th Series engine is turning?

Posted by Owen_Dyneto On 2009/11/24 15:28:58

Guys, if you know your differential ratio and measure your tire circumference or know the diameter (published data in most tire catalogs), you can very simply calculate the rpm in high gear for any speed. And if you have OD and know the gear reduction, it's equally simple. The only aspect of the calculation subject to a bit of error is the fact that the tires under load deform a bit and the circumference measurement made under a static condition may not be the same as under a dynamic condition.