A "more modern" oil with lower ZDDP will be kinder to the exhaust cats, I am told. The Motul 7100 4T does say "meets Harley Davidson specifications" and actually says "special V-Twin 100% synthetic 4 stroke oil" on the back of the container. It has gone up a bit in price recently but Opie Oils usually have some good discount offers. Another good and cheaper option, although mineral based, is Valvoline VR1, some M3W's are using this. In view of the large capacity of the system and frequency of changes, I don't think the oil has a particularly hard life in our engines. The oil temperature rarely exceeds 100c in my car.
Last edited by planenut; 27/06/20 09:53 AM.
