understanding twostroke oils
Amsnow
Synthetics
Synthetic oils are coming of age as cleaner burning and (somewhat) smokeless. Yamaha, Cat, Ski-Doo and Polaris have synthetics. So do Starting Line Products, Spectro, Redline, Klotz and AmsOil, and the list goes on.
Synthetic oils are as close as man can come to nature's best. Synthetics do not retain petroleum by-products. Synthetics are richer in needed anti-corrosion compounds and cleaning detergents. These man-made oils easily pour in frosty temperatures and mix well with petroleum-based products.
Some OEMs recommend synthetic oil (their brand) on motors with exhaust valves. These oils help keep the valves clean and do not build up carbon on the valves. Furthermore, because of the ever watching environmental eye, synthetic oils are gaining attention as the "clean" oil.
In sum, choose an oil that meets NMMA's TC-W3 rating, and is designed for snowmobile motors. The OEMs market their own oil, as do many aftermarketeers and petrochemical companies. Whether you choose an oil that is petroleum, petroleum/synthetic or full synthetic, check its reputation. Ask an engine builder or racer and verify results. It is worth a few minutes of your time and a few extra dollars to protect your $7,000 investment.