OAK BROOK, IL – The ’14 Chevrolet Cruze Clean Turbo Diesel sedan "is arguably the quietest compact diesel on the road," Gary Altman, chief engineer-small and compact cars for General Motors, boasts at a Midwest Automotive Media Assn. briefing on the newest member of the Chevy stable.

Shipments of the Cruze diesel began this month, and while Altman declines to reveal how many, "They are being sold as soon as they hit the ground," he says. "With diesel about $0.42 a gallon less than gasoline, fuel prices are creating a lot of excitement in the car," he said in an earlier interview at the car’s media preview.

One key to the Cruze diesel’s success is its 27/46 mpg (8.7-5.1 L/100 km) city/highway rating from the 2.0L 150-hp turbocharged 4-cyl. and 15.6-gallon (59-L) fuel tank. Chevy brags a 717-mile (1,154-km) driving range, "or roughly Chicago to Atlanta before you have to fill the tank," Altman says.

In addition to its high mileage and extended-range driving, he says a major attraction of the Cruze diesel is its quiet operation, making it difficult to distinguish between the gasoline and diesel versions. "I can't make the diesel quiet outside the car, but I can make the inside as quiet as gas-powered cars."

Altman, who also was chief engineer for the Buick Verano that shares its platform with the Cruze, says the techniques used to silence the Verano were applied to the Cruze.

"There were three key elements used to keep the Cruze diesel quiet,” he says. “Eliminate noise, block noise and absorb noise. In addition to acoustical treatments to glass, we used sound deadeners and insulation in the door panels, dash, instrument panel, console, floors, engine and passenger compartments.”

“We used 100 techniques to reduce noise levels in the Verano, and we used just about all of them in the Cruze (diesel), too.

Altman says what people remember about diesels in the past is the black sooty smoke and noise, but that old image is gone now. The Cruze comes with a diesel particulate filter to cleanup emissions.

“The particulate filter solves the smoke problem, and with the smoke problem solved the diesel smell problem is solved," he says.

Altman admits engineers can’t make the Cruze diesel totally quiet. That will take another evolution of the diesel, but someday the totally noiseless diesel will come, he says. “Perhaps within five years. But it will take changes in combustion technology as well as engine construction, the materials and the composition of the engine in the future."

Upgrades will be costly. The diesel model already carries a $2,000 premium over the gasoline-powered, similarly equipped Cruze. "When volume goes up, prices will come down,” Altman says. ‘When diesels account for 30%-40% of the market, you'll see the cost of the car and the cost of ownership go down."

The success of the Cruze diesel will affect the decision to add diesels in other GM vehicles, he says. "We all want to see what market demand will be. Everybody at GM is watching this car very, very closely. And so is everyone at Ford and (Volkswagen).”

The Cruze diesel does have a couple of issues, he reveals. The first is that the government has no standard on diesel/gas fuel-pump nozzle sizes to ensure diesel nozzles only fit diesel cars and gas nozzles only fit gas cars, so the consumer doesn't accidentally use the wrong fuel. The green fuel cap on the Cruze is clearly marked “diesel,” he notes.

The other problem is of GM's own making: too much modesty in labeling the car a diesel, Altman says. The only telltale ID on the Cruze signifying it's a diesel is roughly an 1-in. (2.4-cm) square metal badge on the deck lid that says "2.0 TD."

He becomes agitated and animated over the lack of a larger badge to let people know the quiet, non-smelly machine runs on diesel and not gasoline.

"We should have a good-size badge on the car," Altman says while extending his hands about 12 ins. (24 cm) apart to signify a mini-billboard size. We need that large badge to educate people that it is a diesel and this is how a diesel performs."