http://www.castrol.com/castrol/secti...tentId=7079436

Castrol has a synthetic 20W/50 motorcycle specific oil that's two bucks cheaper than V-Twin 20W/50 Mobil 1 (at Advanced Auto Parts), it also has a higher overall rating:

"Castrol Power RS V-Twin with TriZone Technology™ is a full synthetic 4-stroke motorcycle oil exclusively designed for modern V-Twin engines, transmissions and primary chaincases. It has been engineered and tested for performance in Harley-Davidson® motorcycles."

"BENEFITSFull synthetic 4-stroke motorcycle oil
Provides excellent protection against thermal and viscosity breakdown under high temperatures generated by air-cooled V-Twin engines
Delivers proven wet clutch performance allowing for smooth operation and protection
Suitable for all Japanese and North American 4-stroke motorcycles where SAE 20W-50 is recommended
SPECIFICATIONS
API SERVICE: Exceeds API SL
JASO (T903): JASO MA-2
VISCOSITY: SAE 20W-50 "

 

Just because something is cheaper does not mean it is better. The zinc level is really what you want to know. The higher zinc content the better the oil.

 

Zink and phosphorus are important to air cooled engines.

 

It is a superb oil. It has a higher viscosity index than amsoil MCV, M1, SYN3, all in 20w50. The 100C viscosity is very high in the range for a 50W, almost a 60W. Even the 10w50 version has a higher 100C viscosity than M1 15w50.

I switched to it a bit ago and this oil in there now has been in stand still traffic at 88F air temp down to 24F this morning. There is none of the extra noise up top like most synthetics give. Starts very easy when full cold.

ZDDP levels are 1140-1200 from lookimg at the MSDS. It is also waaaay more clear than M1 or MCV.

 

I used the Castrol 4T 20W50 on my last change in the block. Castrol 4T 10W40 in the primary, and Castrol 80W90 gear lube in the tranny. It's good stuff.

 

Thanks for the heads up. Nice to know of alternatives. High rated ones even more so. Now to go through the case of syn3 I just bought!

 

Found the zinc level for Mobil 1 v twin its 1750 ppm and the phosphorus is 1600 ppm. couldnt find it for the castrol.

 

Spectro oil is the other oil that has the same ZDDP levels as Mobil 1

 

Bradd penn oil baby check it out

 

Brad Penn is good it is the old Kendall formulation. Red line is another fine choice.