Amid rising concerns about the damaging effects of ethanol-gasoline mixtures on small engines, one outdoor-gear maker has quietly begun to market a canned gas/oil mixture that leaves out the ethanol. At $7.99 per quart, Stihl's Motomix doesn't come cheap. But when you compare the price to the cost of repeated carburetor rebuilds, you can view it as an acceptable form of a centuries-old tradition—paying for protection.
Since ethanol is a form of alcohol, it draws moisture from the air and dries out rubber and plastic seals. The resulting solution also crystallizes to form crusty deposits on parts that are meant to move freely. In large engines like those found in cars, the 10-percent mixture (E10) sold at most pumps shouldn't damage components. The smaller the engine, however, the worse the results—especially if the owner of a gasoline-powered power blower, string trimmer, or other handheld product leaves gas in the engine between uses.
As if concerns about E10 gas weren't enough, the U.S. EPA recently decided to allow the sale of E15 gas, with 15-percent ethanol, for use in late-model cars. Various organizations, including the Outdoor Power Equipment Institute (OPEI), have protested the decision over concerns that E15 has not been adequately tested on smaller, non-road engines. And that once E15 is available at the pump, no warning labels will prevent someone gassing up a car with E15 from also filling a gas can for use in smaller engines.
Motomix is formulated for the two-cycle engines of handheld products, combining 92-octane, ethanol-free gasoline with Stihl's synthetic, biodegradable HP Ultra oil in a 50:1 ratio. The impetus, according to Stihl's press material, is shelf life and reliability. The formulation is expected to last up to two years once you open it. But the absence of ethanol hasn't escaped customers' notice, said Motomix product manager Kent Hall. "If E10 is raising these kinds of issues with products like ours, then certainly E15 is going to complicate them," he says. "With Motomix, customers don't have to be concerned about issues that are related to ethanol, particularly effects on the carburetor and fuel lines."
Motomix, which has been sold in Europe for decades, is available here only through Stihl dealers. Call ahead, though, since dealers can get it only as part of a larger order. I myself bought a can to use in a blower I needed to take to the shop three times last year—even though I'd run the blower dry after each use. I'll report back, albeit anecdotally, on how I do this fall.