GM Shrinks Volt's Gas Tank

General Motors has downsized plans to equip the Chevy Volt plug-in electric car with a 12-gallon fuel tank. The original idea was to give the vehicle an extra 600-mile driving range once the lithium-ion battery pack ran out of its initial charge.

The tank has been shrunk to hold fewer than 12 gallons. GM won’t say exactly how many gallons it will now hold, other than a source saying, “We’re working on that.”

GM’s goal is to begin selling the Volt by the end of 2010.

The original target with the Volt concept was for it to run in battery mode only, without burning a drop of gas, for up to 40 miles — about the distance most folks travel each day — before the lithium-ion battery pack needed to be recharged. 

That goal hasn’t changed. Initially, though, it was intended to be able to travel up to 600 miles more after that using a small on-board gas engine/generator to create more electricity to power the car. It would then need a one- to two-hour recharge, or the gas tank would need to be refilled.

The target now is to travel 360 miles after the initial charge wears off rather than 600.

GM says because most cars travel 40 miles or less each day, there was really no need to have a 12-gallon fuel tank — and the added weight — to extend the range by 600 miles.

“Most cars today have a range of more than 300 miles and less than 400 miles before refueling,” said Jim Hossack, vice president of AutoPacific, an automotive research and consulting firm. “GM didn’t need a longer range because most bladders can’t go 600 miles.

“By going with a smaller tank it means GM can take weight and price out and make Volt a little lighter and a little cheaper, and that’s what you call making an improvement.”