I'm glad you used the phrases "I believe" and "I think".

Oils are broken down by Groups, not Grades. Synthetic oils come in 3 Groups, Group III, Group IV, and Group V. Group III synthetic oil, like HD's Syn 3, is a hydrocracked product made from a fossil oil base. These are often called "semi-synthetics".

Group IV & Group V synthetic oils are both created from a man-made fully synthetic base stock. The difference between the 2 being the type of source used in the base. Group IV uses a polyalphaolefin base, while Group V uses an ester base.

Mobil-1 and Amsoil are both Group IV fully synthetic oils and many independent oil analysis's show them to be top quality products.

 

cHarley is on spot that the "Group" of oil is not a quality factor but rather a base stock factor. With that being said, it is important to point out that (although not motorcycle oils) AMSOIL's XL series of oil are Group 3.

Also, While my memory could be failing me, I could of sworn that I read something on Bob is the Oil Guy a while back that some virgin oil analysis of some Mobil-1 products was showing Group III base stocks.

 

Based on my limited experience and knowledge on the subject, whats more important than what brand of oil to use is the frequency of oil and oil filter changes. That's my .02

 

Extra Virgin Olive Oil!

Just kidding, Mobil 1 15w50.

 

True to an extent. There are some oils that perform much better (or poorer) in certain engines and under different operating conditions. The only way to know for sure what works well for you is by performing used oil analysis.

I will second though that your choice of filter is just as important as your oil. For example, you could not pay me to put a FRAM filter on anything that I own. There are plenty of filters that are top notch though. Cut a few apart and compare them.

 

So does my wife.

 

This is both true and false. It all depends on which specific Mobil-1 oil product you are referring to. Mobil-1 EP (extended performance) labeled oils appear to be a blend of Group III and Group IV base stocks. The base stock also varies depending on the oils viscosity, IE a 0w-40 does not have the same base stock makeup as a 15w-50 or 20w-50. This is where you get in trouble reading oil forums that are not motorcycle V-Twin specific.

Over the past few years there have been at least three oil tests by MC mags, all of which scored Mobil-1 15w-50 oil very high. When comparing the top rated synthetic oils for air cooled V-Twin use like, Mobil-1, Amsoil, Redline, Royal Purple, etc, there isn't any one oil that excels in all categories, nor is one markedly superior overall based on these tests.

IMO, among the top rated oils, the oil you use should be selected on price and availability as they are all good, all far exceed the MoCo's specifications, and are markedly superior to HD's Syn3.

 

Used oil is best.....Its already broken in.

 

- Now there's some good advice on a "beat to death" subject.

 

LOL, I get some good bud once in a while.