Join Date: Apr 2012
Location: 9000 ft. ASL in Southwest Colorado, USA
Thanked 3,645 Times in 1,940 Posts
I agree with jkv357 & cbrlocal... a 10W40 full synthetic motor oil will be more than thick enough for hot climate use. Just make sure the oil you choose is compatible for wet clutch motorcycle use. Motor oils made for automobile use have additives that can cause clutch slippage under load when used in a motorcycle, definitely not something you want.
Generally speaking, oil viscosity becomes more of a concern for engines used in very cold winter temps, particularly at first start up.
Former Factory Test Rider/Technician
Last edited by MotoMike; 04-23-2019 at 11:48 AM.