I think you've hit the bull's eye. Add to your list my old RK, now with 114k on synthetic "car oil." Static compression in 1998 (first check) was 155/160 and in 2006 (last check) 160/160. Oil consumption in 1998, 1 qt./5k miles--in 2007, 1 qt./5k miles. The bike's heads have never been removed. If car oil will destroy this engine, would someone please tell me when this will happen? I'm getting tired of waiting and may die before I find out.

You can use the HD 10-micron (now 5-micron, I think) filters on Evos, and are recommended by HD. I started using them in 1999 on my '96 RK when they were introduced and never had a problem. That's the bike with 114k now.

 

Dude,

I would check with you Harley dealer for void of warranty, Mobil 1 15w-50 is a automotive Race oil for high reving engines, it Exceeds API service SL,SJ/CF Europe A3/B3/B4-02Japan MB 229.1. for gasoline and diesel engines. good for super charged, turbo charged, Muscle cars, and amateur races. not to be confused with Motocycle oil. There are other requirements that oil companies put into the oil for motocycles.....like JASO and others.
I'm saying if it doesn't say Motocycle oil it's not.

-dRE'

 

M1 15/50 is better than most and almost the same as the VT. Do a net search and find an oil analisys/comparison breakdown, I did the research on the net in 98 and have used 15/50 in my FXDX for 30K + miles with no problems and a cooler motor. Ran it in an FZ1 and an FJR1300 both with wet clutchs and had no slipping that I could notice. I run it now in my RoadSlide and noticed about a 10 to 15 degree temp drop, same as my FXDX, I personally run SYN3 in the primary side do to the wet clutch and relitivlly high low end torque of the motor. The FJR had as much or more torque as a 96 CI HD but higher in the rev range so no problem, my FLTR pops the torque out much lower in RPMs so IMO no 15/50 in the primary side.

 

OTAY.....glad you cleared that up for me....man i was in a quandry....you keep believe'n that

 

Gunrunner is absolutely right. 15:50 is within the 10-40/20-50 range of recommended oils, and Mobil1 15:50 contains more V-twin additives than HD Syn3 does. Run the $21.50/5 qts. 15:50 in the motor and the primary and Mobil1 75W90 in the transmission, $7/qt.

Yes, I am an organic chemist. This summer is my 30th year in the business.