Synthetic Oils

Much talk about Syn 3 from the Harley dealers. Let's talk a bit about that oil and it's application

SYN3 is a group III synthetic oil.
Group III synthetics are called hydrocracked isodewaxed mineral oil. In english all that means is that it is dino oil that has been super refined to meet the specs of a low grade synthetic. Group III's do exibit some of the qualities of synthetic like more uniform molecules, higher shear resistance to name a few, but will not stand up to the higher temps in todays motors.
I have never used SYN3. It's produced by Citgo, a Valenzuela company who contracts to whatever oil company will make SYN3 and then slap a HD sticker on it.
Harley Davidson is in the business of making money, not oil.

With that said, the synthetics that are also being discussed here, Mobil 1, redline,Royal purple and a few others are group IV Synthetics and contain no mineral oil at all. They are typically PAO's (Polyalfaolifins) and are 100% man made. Therefore they contain no contaminates that are commonly found in petroleum base stocks. Their resistance to thermal breakdown is well recorded and one of the biggest benefits of a synthetic, and also your engine.
Synthetic oil does not burn like a petroleum oil therefore leaves no or little deposits on your internals, also a benefit to your engine. A synthetic oils lubricity is far superior to petroleum oil because of the uniform molecules, so you will have less wear and cooler running temps, usually in the 10*-15* range.
All good reasons to use synthetic oils. If you change your oil as recommended by petroleum oil companies, 2500-3000 miles you are changing the oil after its useful life has ended. That means at least for some period of time, your dino oil was not doing the job it once did when it was new. This is where the benefits of a synthetic come into play. In most cases the wear and tear being caused by spent dino oil will not be realized until you experience a mechanical breakdown. Your engine will run strong, sound fine, even with scored bearings....until they fail. If you can take documented science and apply it, knowing that a synthetic is causing less wear, cooler running conditions, cleaner running conditions and therefore longer engine life, there is no better reason to use a quality synthetic oil.

I also wanted to address the issue of the oil appearing "dirty" quickly. This can be caused by several things. Residual oil in the sump and oil galleries at the time of an oil change, excessive engine wear, blow-by that could be caused by worn or sticking rings, inferior film strength of the lubricating oil on the cylinder walls, dirty or inefficient air filtration. All good reasons to look at a quality synthetic oil to use in your bike.