Can i run this oil in my 2005 road king with 95 engine and 203 cams in very hot louisiana.The big trucks have good resulests 5/40 rotella synthetic.

 

The big trucks have manufacturers who say use Rotella 5w-40. Your bike should be using at least 15w-50, especially in Louisiana.

 

rotella is designed for diesel engines. either use mobil 1 v-twin or better still amsoil 20w50.

 

Diesel oil is not a bad choice for an air cooled engine. However, you really do need a higher viscosity rating. I use the Rotella in my V8, but wouldn't in my V-twin.

 

I've been using Castrol Syntec 5-50w with great results in my 2003 Ultra. I know some people say not to use car oil, but I've seen evidence of this stuff working. My friends dad was a Chief Chemist at CAT, and all there lab and field test indicated that anything synthetic is superior, and Castrol made the best stuff.

 

What he said......

 

Castrol Syntec ISN"T synthetic. It's molecular reformulated Dino Oil. The last time I checked. The only True synthetics I'm aware of is Redline, Mobil1 and Amsoil.

 

A court case that Mobil lost to Castrol says Syntec and any Group III oil is synthetic. If you go with the idea that a synthetic's molecules are all the same long-chain molecules, then the Group III oils qualify. If you go with the idea that a synthetic is built up, molecule by molecule, and not based on dead dinosaur guts, then the Group III oils don't qualify. But who am I to argue with lawyers & judges?