ROYAL OAK, Mich. — From charging the Chevrolet Volt’s revolutionary power system to washing the car, everything about the extended-range electric vehicle is new, but owners must find the Volt familiar and easy to use.

Racing to meet those twin goals on an unprecedentedly tight schedule, the engineering team working on the Volt has 25 to 30 of them on the road at all times. The deadline is the Volt’s on-sale date in about a year.

“There’s still a lot to do, and not much time,” said Andy Farah, Volt chief engineer. “It’s all part of the natural evolution of any engineering program, but at warp speed.”

Every system, every part must be double-checked and idiot-proofed. Nate Fitzpatrick, Volt engineering manager, sent his 10-year-old son out to plug the Volt in for charging. “I didn’t give him any directions. I wanted to see if we’d made it easy for the owner,” Fitzpatrick said. “He figured it out right away.”

The rush program to get the Chevrolet Volt extended-range electric car on sale in a year has become a 24/7 job for engineers charged with developing the car that’s intended to revolutionize the auto industry and reinstate General Motors as a leader in advanced technology.

“We’re learning all the time,” Farah said as seven of the team met for a recent breakfast debriefing at Athens Coney Island in Royal Oak, Mich., after driving the cars all weekend. The Volt has a 40-mile range on battery power and a small engine that serves as a generator of electric power for longer trips.

“I’ve been bustin’ around all morning, and the engine hasn’t started yet,” Farah said. “The trip computer said I got 260 mpg over the weekend.” Farah recharged the car at home between drives, allowing it to operate nearly entirely on battery power.

The daily test drives have led to changes in everything from how owners will recharge the Volt to an eleventh-hour redesign of the door for its charging port after it fell off in car washes.

The Volt should get an Environmental Protection Agency fuel economy rating of 210 mpg in city driving, according to GM’s projections.

GM built about 80 Volt test cars. Most of the Volts in Athens’ parking lot were built to test a specific system, so the engineers compared notes.

“You’ve got the good aerodynamic package,” Fitzpatrick, the engineering manager, said to Chris Kinser, controls manager, whose Volt was equipped with a nearly invisible air dam below its bumper. “That reduces four counts of aerodynamic drag. I’d give my little finger for four counts of drag,” he said, waving his hand over the table.

“They call me ‘Stubby,’ but it’s a great car.”

Over the laughter, Rob Bolio, lead development engineer, described the crisis of the car wash. The cover for the Volt’s charging port kept falling off.

“The guy who runs the car wash came up to me with a box of parts and said, ‘You might have a problem here,’ ” Bolio remembered.

After a quick revision, Bolio and a design engineer spent four hours taking Volts through the car wash with no damage except to their patience.

“We’re easygoing,” Fitzpatrick said. “When there’s an issue, we give them 24 hours to address it. This has all the challenges of any new vehicle—and all this brand-new technology. It makes the timing particularly challenging.”

For every question any new car must answer — how do the brakes feel, does the navigation system work and a thousand more—there’s a question that’s unique to the Volt.

With the first test cars, Bolio woke up two or three times a night to check on whether they were charging in his driveway. Since then, they’ve added a light to signify the car is plugged in and charging, a subtle “charging now” beep and a timer.

“Owners can set the car to charge whenever they like,” Farah explained. “Just like big commercial customers, they can take advantage of the really low electricity rates in the middle of the night. It’s like a programmable coffeemaker; you tell it when you want the car to be ready to go, and it’ll be charged for you.”

The timer can be set for different charging times on weekdays, weekends, or a unique time for each day of the week.