My local Indy AMSOIL dealer uses the regular 20W-50 rather then the Motorcycle 20W-50 in his personal bike. I asked why the motorcycle oil cost more, he said because people will pay extra for the motocycle bottle.

 

+1 Mobil 1 15w-50 meets/exceeds all of HDs specifications and out performs HD brand oils in virtually every test I've seen. Guess some folks just feel better if they pay twice as much for their oil.

 

What's this cabin fever you speak of? It was 82 degrees here today. Great riding!!

 

Yep, and as I've stated many times before, most of the guys I know with what I would consider very high mileage bikes run nothing but regular old Mobil 1 Synthetic 15W50. It's an excellent oil, costs about half of what you would pay for "motorcycle specific" oils, and as you mentioned is also "CF" rated.

Some people are concerned about the moly content of Mobil 1 15W50 and worry that it might cause potential problems if used in 'wet clutch' applications. Information posted in the Mobil 1 Forum show that the molybdenum content in regular synthetic Mobil 1 15W50 is less than 90ppm, which is less that that of many "motorcycle specific" oils.

Here is a little more information dealing with commercial "C" rated oils;

"The additive packages for C (commercial) certification are designed to promote engine life. The additive packages for C rated oils contain extra buffers and detergents to keep the engine clean and free of acids. C rated oils are far better than S oils at holding and dispersing combustion byproducts and other contaminants, and at not becoming acidic. Traditionally these oils are primarily used in diesel motors, which are very expensive and are expected to last a million miles or more. When an engine rebuild costs $10,000 - $15,000 and puts you out of work for a week or three, you don't mind paying a bit more for your oil. The C certification tests have been largely developed by Mack, Caterpillar, Detroit and Cummins to provide the additives necessary to keep these engines running a long time. The latest commercial certification is CI-4 Plus, which includes extra protection for high temperature high revving motors. Since it's designed for diesel motors, they don't care about no stinkin' catalytic thingies, and CAFE is a place where you get a cup of joe and a donut. CI-4 Plus differs from CI-4 with higher detergent requirements and better sheer stability. The shear stability is exactly what motorcycles need due to running the engine oil through the transmission."

 

ifithaswheelsyoumustuseamsoilrepeathismantrathenbe comeanamsoilrepsoyoucanaffordamsoilandsupportyourh abitbydealingammsoiltoothersammmmmmmmsoil ///'/'//'//'//'//'/'///'

 

Motorcycle oil has a higher sheer strength to resist heat and friction. Oil with out good sheer strength will sludge up sooner.

Don't be cheap. Get the cycle oil.

 

I use car oil in one of mine.

 

I want to offer Member SIXR an apology for my remarks this morning, it should of never happened. After a bad night at work, a long ride home this morning in the rain and almost getting ran over I was a little ticked off and took it out on you. I relize that none of this was your doing.

 

Has anyone ever used motorcycle oil in their car, and what oil would go in what hole in the car? Hurry Spring.

 

Everyone posting an answer so far has missed the most important issue in SIXR's question. He apparently believes his Harley has a dry clutch.

SIXR, your Harley, unlike most metrics, has a separate oil resevoir for the clutch and primary, and another for the transmission, unlike metric bikes which have but one "hole", but it does have a wet clutch. Very few bikes made nowdays have a dry clutch, but many older bikes, like my classic Triumphs, do.

Lower viscosity oils, such as 5x30, have friction modifiers to increase gas mileage. Their oil bottles will have a "Starburst" symbol, indicating "energy conserving." Those are the oils you should never use in a wet clutch operation, as they may cause slippage. Spend a half hour in Wal Mart and look at all the oil bottles, and different viscosities. You will see the Starburst Energy Conserving symbol only on the lower viscosity oils.

The oils your Harley requires have higher viscosity and will not have friction modifiers. As a previous poster replied, oils meeting the diesel requirements as specified in your owners manual are suitable.

This forum is full of oil threads. Everyone has an opinion. Some are just plain wrong. More than decade ago Motorcycle Consumer News did a series of articles on "car vs motorcycle specific oils," and found no appreciable difference.