The government's plan to dilute your gasoline, explained

With gas topping $4 a gallon this week amid the war with Iran, the EPA announced a plan to lower prices and stretch America's fuel supply by cutting more of it with ethanol. Will it work? Probably not. And as Joel, Kyle, and Andrew explain, it could actually ruin your car's engine. Ethanol is an alcohol made from corn, and it's commonly added to gasoline as an oxygenator that helps it burn more cleanly and raises the octane rating. We used to use lead, but... that didn't work out. But there are downsides: it's less energy dense than uncut gasoline, so the more ethanol you add, the less efficient your car's engine runs. It's also a solvent, so it will eat away at rubber seals, hoses, and plastics in engines not designed for it. And it degrades quicker in higher temperatures, creating more smog during the summer. Normally, a gallon of gas is about 10% ethanol, 90% gasoline by liquid volume. E15 gas, which is 15% ethanol, is sold in a number of states during the cooler months as "88 octane", and it's a bit cheaper—because you're literally buying less gas and more ethanol per gallon. Oil companies are typically banned from selling it from June to September because of the smog issue, but the EPA is now waiving the rule to encourage refineries to make more E15. But if your car was made before 2001, even that 5% bump in ethanol content can really screw up your engine. E15 gas will also damage smaller two-stroke engines in motorcycles, lawn mowers, and boats. And even if you have a newer car, there's still a risk that comes with opting for cheaper 88 octane—especially if your car requires premium fuel. Stories mentioned in today's episode: The Feds Plan To Start Diluting Gasoline This May: Explained Learn more about your ad choices. Visit megaphone.fm/adchoices