[joeling]

Hi,

I have run the 8XL successfully with 5S 4000mah with average run time between 10 to 20 minutes geared 13/46 for buggy.

Once upon a time, I have also run a 7XL on 6S without issues on the motor again geared 13/46 (there were other issues - plastic spur melting...)

So I guess running 6S on 8Xl is probably ok but not recommended. If I'm not mistaken, the bearings of the 8XL is rated up to 50k rpm only.

Oh, I have also run 6S on 7XL in a savage successfully using a 60mm fan + heatsink on the motor but the gearing is not as high as that of a buggy's.

I hope this is of help.