popular science says:
Other Alcohol Issues
Alcohol is corrosive and can degrade plastic, rubber or even metal parts in the fuel system that weren’t engineered to use alcohol-bearing fuel. Consequently, that antique Evinrude outboard or ’60s lawn tractor you bought at the swap meet might need some upgrading to stay together on today’s gas. That means corrosion-resistant tanks, alcohol-tolerant rubber lines, seals and fuel-pump diaphragms, and plastic fuel-system parts that won’t swell up in the presence of alcohol. Vintage boats with internal fiberglass tanks often have issues with the coating inside the tank failing, sometimes requiring massive structural modifications. Highly tuned two-stroke engines will run leaner (and consequently hotter) on the lower Btu/gallon alcohol mix, potentially leading to melted pistons and scuffed cylinder walls. Alcohol will also scour varnish and deposits out of the fuel system that have remained in place for years, which will eventually wind up in the filter or main jet, choking off the engine’s fuel supply. Worse yet, the alcohol itself oxidizes in the tank and produces a tenacious brown glop that’s far more damaging to fuel systems than the varnish we’re used to seeing in pure petroleum fuels. In warmer weather, you can see varnish starting to form within a month of dispensing fresh fuel into a vehicle tank or storage can.
Advice
The common question I get: Where can I buy alcohol-free gasoline? You probably can’t, except at a very few stations, and odds are it’s very expensive high-octane racing fuel that’s not legal for road use.
To avoid phase separation, avoid long-term fuel storage. Trash that old 5-gallon can with the rag stuffed into the filler neck and trade up to a 2-gallon can with a decent, vented cap. I used to recommend storing outdoor power equipment, boats, ATVs and motorcycles with full tanks to prevent rusting. Now I recommend draining the tank, running the engine till it quits and then fogging the inside of the tank and the cylinder with oil to prevent corrosion. No E10 in the tank equals no water absorption and no phase separation.
We’ve always recommended using fuel-stabilizer products for gas-powered vehicles or tools that aren’t regularly used. E10 makes that advice even more compelling. We’ve tried products formulated for blended gasoline from Star Tron, Eastwood and Sta-Bil. There are others. Beware of products that claim to prevent phase separation: It’s unlikely that they can eliminate the phenomenon, although some products do claim to delay it.
Read more: E15 and Engines – Can Ethanol Damage my Engine – Popular Mechanics
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