v4rick
Junior Member
Re: The debate is over. Rotella T wins!
Good one, "81".
Good one, "81".
Friction modifiers have long alkyl chains for consistent viscosity, and are polar compunds for adhering to metal surfaces and reduce surface friction.
My MOM says to use 10W-30 from 10 - 70 degF and 20W-40 from 50 - 110 degF. The Yamaha dealer doesn't sell 20W-40. They said 20W-50 is fine and that is what they sold to me when I purchased my 2008 FZ6. I live in Florida, so it is probably just fine. However, the morning lows are getting down to about 34 degF and I am still riding to work. The morning chill is a small price to pay for the 50 - 60 degF afternoon ride home. Anyway, I am a little concerned about oil, but remember the oil will act like 20W at the lower temps, so there shouldn't be much difference between 20W-50 and 20W-40 when the ambient temp is 40 degF. Right? I don't think there is any problem with it. And if there is, I have the receipts to back it up. Why would Yamaha discontinue the very oil that they recommend (for my 2008 FZ6) if the 20W-50 would be harmful? They wouldn't. That said, I notice that Amsoil recommends their 20W-50 for larger V-twins and such. They recommend 10W-40 for smaller Japanese bikes. When my engine is broken in and if I decide to change to a synthetic, I will probably use 10W-40. Actually, I don't know why the manual doesn't specifically call for 10W-40. Maybe they do in the 2009 MOM?