With gas prices holding at their near-record levels, Iowa drivers are looking for ways to make every drop go as far is it can. But a car-maintenance expert cautions against running your tank bone-dry. Jerry Burns is automotive instructor at Des Moines Area Community College. He says the problem with running the tank dry, he says, is that your car’s fuel pump depends on the fuel to cool it. The fuel pump in today’s cars is located in its own little module inside the tank where it’s surrounded by fuel that helps cool it. Run it dry, overheat the fuel pump, and you’ll pay your mechanic a few hundred dollars for a new one. Burns says there’s another problem trying to with burn those last drops of fuel. Water settles to the bottom as it’s heavier than gas, so when you’re almost out of fuel and you’re taking gas from the very bottom of the tank you’re drawing up that water, dirt and debris into the fuel line, plugging up the fuel filter or injectors. If you pass one of those pumps selling a gas blend that’s 85-percent ethanol, Burns cautions not to assume your car can use that fuel. There aren’t many of them on the road, he says. “You have to make sure that the vehicle is E-85 compatible,” he says, “because the fuel systems are completely different.” Most e-85 systems will have a sensor to detect what portion of the fuel mix is alcohol, and they’ll have stainless-steel fuel lines to reduce the chance of corrosion. Burns says they also have different injectors. If you put 85-percent ethanol fuel into a vehicle that’s not E-85 complaint, it probably won’t run. If it does, Burns says, you’ll have some problems.
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