Originally Posted By: Mike_dup1
Most automotive engine oil is developed to minimize friction and maximize fuel economy.
I think this is mainly a US issue,hence the use of thinner oils and friction modifiers.One of the reasons the rest of the world uses thicker oils.
As far as gear wear goes,Yamaha had 5th gear problems with the XT600 for a long time.I presume every oil in the world has been tried (and they weren't sold on the US market,only the early ones) Yamaha changed the primary drive ratio to increase gear speed,and fitted an external auxiliary 5th gear oil supply.Owners learned not to use 5th gear at low speeds. Not oil related at all.
I had a 2 stroke Yamaha (DT230) that wore out 6th gear the same as 5th in the XT600.Engine oil was recommended by Yamaha,but don't know what previous owners used.
I worked on BMC Mini's for many years,they had a lot of gearbox problems - but none caused by the shared engine/gearbox oil.
Most automotive engine oil is developed to minimize friction and maximize fuel economy.
I think this is mainly a US issue,hence the use of thinner oils and friction modifiers.One of the reasons the rest of the world uses thicker oils.
As far as gear wear goes,Yamaha had 5th gear problems with the XT600 for a long time.I presume every oil in the world has been tried (and they weren't sold on the US market,only the early ones) Yamaha changed the primary drive ratio to increase gear speed,and fitted an external auxiliary 5th gear oil supply.Owners learned not to use 5th gear at low speeds. Not oil related at all.
I had a 2 stroke Yamaha (DT230) that wore out 6th gear the same as 5th in the XT600.Engine oil was recommended by Yamaha,but don't know what previous owners used.
I worked on BMC Mini's for many years,they had a lot of gearbox problems - but none caused by the shared engine/gearbox oil.
