Hi Doc1972,

I’m a big believer in using synthetic oils for engines and gear boxes. I’m running Amsoil in all 3 holes of my Road King. I’ve been using it for 30 years in all my vehicles with great results.

The chatter you hear could be a number of things. I don’t believe synthetic thins more than comparable weight dino oil, so that’s not the problem. I agree with Grendel4… could be cleaner internals after the syn loosen engine build-up. Might also be less heat expansion since an engine on a good synthetic runs cooler.

Anyway, if you love your ride and plan to keep it awhile, I’d stick with a full synthetic.

I pay close attention to independent motor oil studies and test results and never seen any reason to run anything other than Amsoil. My distant second choice is Mobil-1. HD Syn3 is down the list quite a bit, but still better than any petroleum based oil.

By the way, in case you are concerned about warranty issues if you use anything other than HD’s oil… don’t. It would be against federal law for HD to void a warranty or service contract just because their oil wasn’t used; Google “Magnuson-Moss Act” for details :-)

Ride safe brother.

 

I changed to syn-3 on a 2006 Low Rider. It sounded like rocks in a prince albert can. I bought Mobile V-Twin on the way home. And immediately changed it out.

Noise went away. I just put it in my 2007 FLSTC.

Mobile synthetic is compatible with other oils. So you can change back.

 

Redline[my personnel fav.], Delvac1, Motul5100, and Amsoil are the only pure synthetics still made in this country.

 

I hear what you’re saying, but I don’t get it; an increase in motor noise, probably valve train, just from using synthetic? Something doesn’t add up.

I agree, on the surface, based on the explaination provided, it seems fair to attribute this noise difference to synthetics verses dino oil, but there has to be more to it. If you are comparing the same viscosity oils, there should be no significant noise increase in the valve train in a solid, problem free engine just from using good synthetic oil.

There’s plenty of documented, independent studies that prove synthetic’s are superior at reducing friction, wear, run cooler, and prolong engine and gear box life. This with my own experience keeps me using it.

Also, remember that HD Syn3 is a blend; 60% synthetic and 40% petroleum. You can read the details in the materials safety data sheet. Syn-3 is made by Sunoco based in Philadelphia. The law allows a blend with more than 50% synthetics to be labeled as full synthetic, even though it isn’t 100% synthetic.

HD says that SYN3 can be used in brand new bikes from day 1. This alone is an eye opener. A quality, true full-synthetic oil reduces wear so significantly that if used in a brand new motor it would never break in properly.

For an engine already broke in, and immeadiately in the trans and primary, I prefer Amsoil for the best return on your investment.

While Amsoil isn’t certified by HD, that merely means HD hasn’t tested it; most likely because of financial reasons. HD provides oil rating specifications required for their bikes. Amsoil meets and exceeds them which is why HD says it is okay to use it.

HD doesn’t recommend anything except their HD label. It’s a business decision, not a technical or mechanical one. HD oil pays them royalties and profit for every quart sold, and they stand to profit when motors wear out a little quicker (they would never admit this, but it’s a common sense fact).

If you want to dig in a bit more, check out this article published years ago in American Iron magazine. It’s one of my favorites, but there are tons of other supporting docs out there: http://www.harley-performance.com/ha...il-debate.html

Take care brothers. Ride safe!