Diesel Enables 55-MPG Large Car, Bosch Says
Tom Murphy Ward's AutoWorld, Nov 1, 2009 12:00 PM

A steady rollout of new diesels, gasoline direct-injection, stop/start systems, high-efficiency alternators and cheaper lithium-ion batteries factor into Robert Bosch LLC's product offerings to help auto makers meet the 35.5-mpg (6.6 L/100 km) fuel-economy mandate that takes effect in the U.S. in 2016.

In the long term, all powertrain paths lead to a full electric vehicle, the world's largest auto supplier says. But for at least the next 20 years, efficiency gains and technology advances surely will keep internal-combustion engines competitive with an anticipated wave of EVs.

On the diesel front, alone, Bosch expects higher injection pressures to allow better atomization of fuel, translating into lower emissions and fuel consumption and reduced noise.

Today's common-rail diesels are about 40% more fuel-efficient than a similar sized port-injected gasoline engine. Many hybrid-electric vehicles offer similar gains.

Because diesels will continue to improve, the supplier expects diesel market share in the U.S. to double from 5% today to 10% by 2016.

Packaged with other technologies, diesels are capable of some outrageous fuel-economy gains, says Johannes-Joerg Rueger, senior vice president-diesel engineering for Bosch in North America.

For instance, in the large-car segment, where gasoline port-injected V-8s are not uncommon, a much smaller turbodiesel with higher boost pressures, optimized exhaust-gas treatment and start/stop technology can more than double its fuel efficiency to almost 55 mpg (4.2 L/100 km), Rueger says.

As part of a media event, Rueger shows a slide indicating 13 new diesel vehicles are headed for the U.S. market between now and 2014. Some of those will come from OEMs currently not selling light-duty diesels in the U.S., he tells Ward's.

Diesels make up about half the new-vehicle market in Europe, and most small diesel engines available there are not offered in the U.S.

But most of them “could be made compliant” with U.S. emission regulations in place for the next several years without adding significantly to the sticker price, Rueger says.

German brands such as BMW, Audi, Volkswagen and Mercedes-Benz have made a concerted push into the U.S. market with new clean diesels.

Audi has said it intends to offer diesels for every nameplate in its portfolio, from the A3 hatchback to the Q7 cross/utility vehicle. The all-new diesel-powered VW Jetta TDI and BMW 335d each earned Ward's 10 Best Engines honors earlier this year.

“We know the German auto makers view diesel as the most powerful tool to meet the 35.5-mpg target,” he says.

Beyond diesel, Bosch will remain entrenched in more efficient gasoline systems as well. By 2016, Bosch estimates the share of GDI will triple to 16% worldwide and 33% in North America, alone.

Starting with the '10 model year, Audi will be the first OEM offering all gasoline engines in the U.S. with DI.

Ford Motor Co. also is heavily invested in GDI with its new EcoBoost turbocharged 3.5L V-6, offered in the Flex, Taurus SHO, Lincoln MKS and others. Bosch supplies the fuel-injection system and powertrain controller for EcoBoost.

Barb Samardzich, Ford vice president-global powertrain engineering, was a guest speaker at the Bosch event and says a 2.0L I-4 EcoBoost engine arrives in the U.S. next year, as does a 1.6L EcoBoost I-4 in Europe.

EcoBoost will help Ford downsize its powertrain offerings. Samardzich says Ford's mix of 4-cyl. engines will triple, from 10% in 2005 to 31% next year. Meanwhile, V-6s will make up 34% of the mix next year, down from 46% in 2005, and the V-8 mix will drop to 35% next year from 44% in 2005, she says.

Also, Bosch says stop/start systems that shut down the engine at traffic lights will take hold in the U.S., as they have already in Europe. Bosch's system has been deployed on more than 1 million vehicles, including the all-new Porsche Panamera.