I just got a used 2012 Harley Heritage Classic. It has 5100 miles on it. I want to use a synthetic oil, partially to help lower the engine heat.

What is your opinion of the best synthetic oil to use for my bike?

Thanks,
Wayne

 

Synthetic polyalpha olefin is the best.

 

pick whichever one has the coolest label in your opinion

 

Castrol Power RS for the JASO MA/MA2 spec oils and Valvoline VR1 synthetic. Both are the quietest. VR1 is quieter and I have to run 85 for an hour straight in 85 degree temps to get my oil to 210 with VR1.

Any oil with a 100C cSt viscosity of 20.0 or higher with a Viscosity index 150 or more will be a better oil than ones with specs lower than them numbers. Not all 20w50 oils are the same 20w50. Some are actually pretty darn thin at 100C.

Look up some product data sheets and keep them numbers at or above the numbers I posted and you will be fine. Amsoil Z rod is a great oil for our motors. We dont need the added friction JASO spec calls for in the motor, but its perfect in the primary.

 

Keep in mind that Big Twins have 3 holes and not 2 holes as a Sportster does..................

 

Yup, two or three holes, the one that feeds the motor, only feeds the motor, two or three holes. No need to dump JASO high friction oils in a Harley motor.

 

Congatulations on the new baby...boy or girl? Johnson's baby oil is best.

 

According to the Indian riders Dino oil cools the engine more than syn does.

 

I'd think so too but because synthetic is thinner, it's supposed to cool faster in the oil tank.

In the 70s, we used to use 90w Valvoline. We could only get it at an Army and Navy store.

 

I still use Dino, Valvoline 4 stroke MC oil, 60 weight right now cause it is 100+ here during the day.... 50 in mid temps, 20/50 winter.