Considering that the Chevy Volt is designed to be a primarily electric vehicle, it’s fair to wonder why it would need a specialized gas tank. Isn’t the main point of using an electric vehicle to avoid using gas for all but emergency situations? Yes it is…and it turns out that’s exactly why Chevy had to design a specialized gas tank and computer monitoring system for the Volt.
For many Volt owners, their ultimate goal is to avoid the gas pump as much as possible, if not entirely. The better they get at using solely the electric engine, the longer the gas in the tank will sit. As the gas sits dormant in the tank, it begins to break down. “Gasoline readily evaporates at normal ambient temperatures and it also degrades over time from oxygenation and condensation,“ said Jon Stec, fuel system integration engineer for the Volt. In order to ensure that the gasoline in the tank doesn’t hurt the Volt’s performance or emissions when it is needed, engineers pressure sealed the 9.3 gallon steel fuel tank to contain the gasoline vapors. Stec added, “Using a sealed tank limits this evaporation when the engine is off.”
The pressure sealed tank is made from 1.4 millimeter thick hot-dip tin-zinc coated steel that resists corrosion inside and out. Though the tank is super strong, Chevy added both pressure and vacuum relief valves to ensure the tank’s integrity. This special tank design is integrated with a computer system that monitors gas engine use (or lack of it) and reminds the driver to engage the engine for maintenance purposes after six weeks of non-use. If the driver decides to ignore the message, the Volt will force the gas engine on in order to cycle the gas and keep things in the gas engine lubricated.
Stec put the system’s forced fuel use into perspective: “For the driver who starts the year with a full tank of 9.3 gallons and runs 15,000 miles on electricity, the maintenance mode will use just enough gas to average a very respectable 1,613 miles per gallon”