And that is where you have to be careful about oil and read the seal It should NOT state "energy conserving" on it. You are right, most will have the friction modifiers so when you find the brand and weight you want, check the label. Actually checking the label would be a good idea in all purchases.

 

I am retired also and don't waste money.
But I like and use Mobil 1 V-twin, in the motor and pri. I also prefer the Mobil 1 GL 75-90 in the tranny, it feels and shifts better than a heavier grade in our milder Indiana summer temps.
I tried another brand of heavy GL, Bel-ray 80-140 at our dealers sugg, felt way to heavy and dropped it out after a couple weeks. Went with Mobil 1, GL 75-90 for the last 20k.

 

i also am retired but i use the most exp oil i can find by the way i only use redline in my bike and wifes bmw, and there shockproof in my tranny, somethings are penny smart and pound foolish you can do some fuzzy math on all these numbers, but for me i feed my dogs the best dog food why woulden`t i treat my bike any different, if you feel saving ten dollors will bust you than sell the bike

 

i run the 15/50 in my engine, but use good ol formula + for the primary. redline gear oil in the tranny.

 

I use Mobil 1 15w50, had a his done, had excellent report. Bike doesn't know the difference, doubt if any naysayers could either.

 

That is one of the most rational statements I have read in ANY oil thread!

 

the op asked what the difference was. i understand that due to epa regs that limit the amount of phosphurus and zinc v-twin is allowed a higher level of these because is labeled for m.c. use. phosphurus and zinc are important for anti-wear properties in a flat tappet cam engine. rottela used to have among the highest levels but no more again due to epa.

 

Just to clear up any confusion, Harley's use roller cams, not flat tappets.

 

Here is a man who knows what he's talking about & answered the question.

 

M1 15w50 and i change every 5000 miles not 3000 and their is plenty of oil life left even at 5000 mile oil change intervals. Synthetic Mobile 1 can probably easily go safely to 10000 miles. I read a report where they changed the oil at 13000 mile intervals (car) and the engine looked brand new after 45000 miles about 4 oil changes.. I'll stick to 5000 on my Sporty without worry.