[StuBeeDoo]

Can someone tell me, please, the difference between SCX's RK-41 motors and the RK-42 version?  My go-to site for motor specs (Slot Car News) doesn't list the RK-42.  For clarity, the RK-41 is fitted in the MGA, and the RK-42 is in various cars - including the Audi A5 DTM and Mercedes AMG C-coupe DTM.

I suspect the -42 is a higher-revving motor, but I'd like to get an idea of how much faster.

Thanks in advance