General Motors will unveil later today at the Chicago Auto Show the Chevrolet Cruze turbocharged diesel, an all-new variant for its best-selling small car and a gamble that North American consumers will gravitate to the performance and fuel economy the engines offer despite their premium fuel costs and checkered past.

The ’14 Cruze Clean Turbo Diesel will arrive at Chevrolet dealers this summer with a starting price of $25,695.The 5-passenger sedan will be sold with a 6-speed automatic transmission only.

“Cruze Clean Turbo Diesel fills an important role in Chevrolet’s diverse 4-cyl. lineup and is primed to win over diesel devotees and compact-car buyers with its performance, torque and fuel economy,” Chris Perry, vice president-marketing at Chevrolet, says in a statement.

“We leveraged engineering expertise from around the globe to develop a world-class, low-emissions engine to give U.S. and Canadian customers a car that’s both fun to drive and practical at the pump.”

GM expects consumers will go for the Cruze diesel’s combination of a peak 42 mpg (5.6 L/100 km), which with a 15.6 gallon (59 L) fuel tank will give it greater range than the Volkswagen Jetta TDI, and a segment-best 148 hp and 258 lb.-ft. (350 Nm) of torque at 2,000 rpm.

The most fuel-efficient Cruze currently on the market, a ’13 Eco model with a 1.4L turbocharged gasoline engine mated to a 6-speed manual transmission, also achieves 42 mpg, according to Environmental Protection Agency estimates.

GM sources told WardsAuto in 2011 the Cruze diesel could achieve upwards of 50 mpg (4.7 L/100 km), a mark that now appears unlikely although EPA testing remains under way.

But Americans prefer automatic transmissions over manuals, giving the Cruze diesel business plan additional legs, says Cristi Landy, director-marketing, Chevrolet Small Cars and Electrified Vehicles.

“Chevrolet has had a lot of success globally with our diesel engine, and we looked at what the competition is doing, and based on our technical capabilities we wanted to bring (it) to the U.S.,” Landy says on a conference call ahead of the Chicago unveiling.

Landy does not provide a production estimate for the Cruze diesel, but GM executives have said it would comprise about 10% of sales, or about 24,000 units based on full-year 2012 deliveries. Production also will ramp up slowly, she adds, with targeted distribution beginning on the West and East coasts.

The gasoline Cruze packs a weaker 200 lb.-ft. (271 Nm) of torque, and GM executives believe both diesel enthusiasts and those new to the segment will buy into the performance elements of the oil-burner.

“There are people out there who like diesel, no matter what, for the performance and efficiency,” GM North America President Mark Reuss told WardsAuto shortly after announcing production plans for the diesel Cruze in 2011. “We’ve got a good car.”

According to the Diesel Technology Forum, a lobbying group for diesel suppliers and auto makers, buyers of cars with diesel engines cite performance as their No.1 reason for purchase.

But diesel fuel currently commands a price premium of $0.35 over gasoline per gallon, according to the American Automobile Assn., and only about half of U.S. filling stations carry the fuel. Among some consumers, the engines carry a negative reputation fueled by Detroit’s unsuccessful introduction of diesel engines in the 1980s.

Between 1977 and 1984, GM ranked as the No.1 producer of U.S. passenger-car diesels, and sales of its 5.7L V-8 peaked in 1981 at 310,426 units, according to the WardsAuto Yearbook.

The auto maker added a 4.3L diesel V-6 in ’82, only to see high gasoline prices plummet, erasing the psychological incentive for diesel. Consumers also had grown tired of the diesel’s sluggishness in cold weather, smoky exhaust and unruly clatter.

Price cuts proved unsuccessful and demand shrank to less than 30,000 units annually within 12 months. A specially built plant in Lansing, MI, produced at 10% of its intended capacity.

As tighter national and California emissions standards doomed the business case for diesels, the last diesel-powered passenger car GM sold in the U.S. was the ’86 Chevy Chevette subcompact with a 1.6L oil-burner.

However, the advent of high-pressure, common-rail direct fuel injection more than a decade ago solved most of the problems associated with previous-generation diesels. Today’s engines burn 90% cleaner and are much more quiet and efficient.

With strict new fleet average fuel-economy rules rising to 35.5 mpg (6.6 L/100 km) in 2016 and peaking at 54.5 mpg (4.3 L/100 km) in 2025, auto makers must diversify their lineups with fuel-sippers to remain compliant. Gasoline prices also are expected to rise, likely closing the price difference between the two fuels.

GM says the Cruze diesel will meet U.S. emissions standards, which are tougher than current European levels, and will be sold in all 50 states.

GM applied know-how from its Italian and German engineering groups to homologate the Cruze diesel for the U.S. off a proven engine already used in the Opel Astra, Insignia and Zafira. The take-rate on the diesel engine among European Cruze customers last year was about 40%, or 33,000 units.

“(The) Cruze Clean Turbo Diesel is the most sophisticated passenger-car diesel engine GM has ever produced,” Jens Wartha, GM global program manager and chief engineer for the Cruze’s diesel engine, says in a statement. “We merged European diesel expertise with the real-world driving preferences of North American consumers.”

GM engineers relied on diesel knowledge honed by its truck program to adapt the Cruze diesel for North America, incorporating the ability to perform in a wider range of driving conditions, including colder climates and higher altitudes. The auto maker also added an “overboost” feature, increasing torque to 280 lb.-ft. (380 Nm) for stronger acceleration for up 10 seconds.

Greater thermal efficiency, a higher compression ratio and an enhanced combustion process contribute to the Cruze diesel’s high fuel economy, when compared with a gasoline engine of similar displacement.

Highlights of the Cruze diesel include central direct injection, which positions the injector straight above the center of the cylinder, enabling a 16.5:1 compression ratio and enhancing power and combustion efficiency. Mounting the injector at an angle, as is the case with most engines, creates the risk for unburned fuel on the walls of the combustion chamber.

GM also uses the latest piezo-based fuel injectors, which are more expensive than solenoid-equipped units but capable of multiple injections per combustion cycle to reduce noise and boost performance.

In addition to friction-reducing technologies such as a variable-displacement oil pump that requires less energy to provide lubrication at all engine speeds, GM adds sound-absorbing items specific to the Cruze diesel, including a unique dash mat and hood blanket.

“We spent a lot of time on noise and vibration,” says Gary Altman, chief engineer-Chevrolet Small Cars.

To meet U.S. and Canadian diesel emissions regulations, the Cruze diesel uses an exhaust-gas recirculation control system, diesel particulate filter and urea injection after-treatment to reduce oxides of nitrogen emissions.

The Jetta currently does not require urea after-treatment, although Volkswagen is expected to add the technology as emissions rules tighten.

The Cruze diesel uses a 4.5-gallon (17 L) urea tank, providing at least 10,000 miles (16,000 km) of driving between refills.

The engine weighs 408 lbs. (185 kg), or slightly more than either the 1.4L turbo or 1.8L naturally aspirated gasoline engines currently offered in the Cruze, and is B20 biodiesel capable. The engine will be built at GM’s plant in Kaiserslautern, Germany, and shipped to Lordstown, OH, for installation.

The ’14 Chevy Cruze Clean Turbo Diesel will carry a $1,500 premium compared with a ’13 Jetta with an automatic transmission. The Jetta’s 6-speed dual-clutch automatic is more advanced than the Cruze transmission, but Landy says buyers of the GM model will get more content.

“We’re offering (diesel) in one model, which is a pretty high-level trim,” she says. “We feel it is very competitive and a value versus the Jetta.”

jamend@wardsauto.com