How General Motors Deals With Stale Gasoline in the Chevrolet Volt

Chevy Volt On Display

If you own the Chevy Volt and drive less than 40 miles a day, then you will almost never have to visit a gas station. General Motors engineers took this into consideration when developing the gasoline storage system on the Volt. I recently had the chance to gas up the Volt, and learned just how much technology and computing power was applied to the refueling event. After all, when your car needs a gas fill-up only a few times a year, you have to make sure that storing gasoline for weeks or months won’t increase emissions.

To release the gas nozzle inlet, located on the rear passenger side, the driver pushes a small button on the driver’s door. The gas release button is a little hard to see at first, but it’s right above the electric charging inlet release button. (The charging inlet, where you juice up on electricity every day, is on the front driver-side of the car.)

When you hold and release the gas door button, you need to wait a moment. An indicator on the dash tells you to “wait to refuel.” That gives a vacuum pump enough time to evacuate the pressurized tank and pump the vapors into a carbon canister. The gas tank is otherwise completely sealed.

The Volt’s computer system is monitoring this activity—keeping track when the gas door opens and closes, how much time has passed, and how many EV miles you’ve driven since the gas engine was last called into action. If you open the gas door, but don’t put in any gas, the Volt knows. The car’s system is double-checking to make sure that new fuel has been added, because old stale gasoline is potentially bad for the system and bad for emissions. An outside temperature sensor is even keeping track of hot days to determine if the fuel might be cooking.

If you haven’t burned fuel for a while, the dashboard display will encourage you to burn some gas, by driving the vehicle beyond its 40 miles battery-supplied power. You can ignore the call to action, but after two warnings about the need to drive using some gasoline, the car will take matters into its own hands. The Volt will then start up the gas engine in order to burn off stale gasoline, circulate engine oil, and pressurize the engine system.

When the car completes this “engine and fuel maintenance mode,” it shuts down again, giving the reins solely back to the electric motor. At that point—for drivers who stay close to home—the gasoline is again left in reserve for days, weeks or months, until your next rare and infrequent trip to the pumps.

Source: Plugin Cars