On a recent trip to the mountains of Colorado, I noticed a sticker on a gas pump, one that’s unfamiliar to me in Albuquerque, New Mexico. The sticker said, “Clear Gas Ethanol-Free,” and it has not only a high octane rating but a much higher price. In most urban areas we’re used to seeing E85 or other flex fuel stickers on pumps, but “non-ethanol” is a rarity. What is clear gas, or non-ethanol gas, and should you use it in your car or truck? Does it give you better gas mileage?

Clear gas is gas that is made only from petroleum products and not blended with ethanol or any renewable fuels. Every other kind of gasoline at the pump is blended with ethanol. Ethanol is an additive made from corn, grasses, sugar cane, and different plants. It’s added to fuels to reduce emissions levels. Ethanol levels are different from the grades of gas you buy, which are based on octane.

No. Ethanol is not bad for your engine or fuel system. Since the 1980s every vehicle has been designed to run on a small blend of ethanol and gas, like E10. But ethanol can absorb water and that means that if it sits for too long (months or years) it can harm your engine. That’s why boaters use ethanol-free gas: they’re on the water when they use it, and then don’t typically start their boat’s motors for months at a time.

But ethanol is better for the environment. Ethanol use reduces greenhouse gas emissions, dissolves in water, and is renewable. Any car or truck engine can burn ethanol just fine. Too much ethanol, on the other hand, is bad. A car that isn’t designed to run on, for example, E85 fuel will run poorly because the computer isn’t able to adjust your engine timing to compensate for that much ethanol.

Small engine manufacturers like Husqvarna, which makes gas-powered chainsaws and lawn mowers, recommend you use ethanol-free gas, but not for performance reasons. Instead, small-engine manufacturers understand that trimmers and mowers sit, often for months. During that time the ethanol absorbs water from the atmosphere and that can cause problems with lubrication. Small equipment is approved for E10 fuels and they won’t hurt the engine, just make sure you drain it all or store your gasoline properly before you put your chainsaw away for months.

It depends. Ethanol does give off less energy when burned, so that means that if you’re using a blended fuel you can get less power. But, many engines are designed specifically to run on blended fuels and not see much or any power loss. In fact, NASCAR uses blended fuels to make monster power.

However, some motors, especially older ones and those with carburetors, may respond better to clear gas and produce more power.

If you’re looking for ethanol-free gas by zip code, a number of websites like pure-gas.org, show locations of gas stations that sell non-ethanol gas near you. But, since non-ethanol gas is often harder to come by, you may have to visit several gas stations to find it. Most major branded gas stations like Exxon or Chevron stations don’t carry non-blended fuels. Instead, you’ll likely have to find an independent station.

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