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It will hit European streets soon, but Subaru’s new boxer diesel engine is still at least two years away for North America.
It’s a world first: a boxer turbo-diesel in a passenger car. Subaru has announced that a 2.0-liter four-cylinder diesel engine will be offered in the European versions of the 2008 Subaru Legacy and Outback beginning in March, following its debut at the Geneva auto show.
But the boxer diesel will be two or three years old when it becomes available in the U.S., Subaru engineers tell us. The Legacy, Outback, and Forester are likely candidates for diesel power in North America.
The concept is intriguing: a horizontally opposed diesel engine and Subaru’s symmetrical all-wheel-drive system, both squeezed into vehicles with restricted amounts of space—there’s no room for the package to take up any extra width or length. Compared to the 2.0-liter gasoline-fired four in Subaru’s stable—but not available in the U.S.—the diesel has a decreased bore, an increased stroke, and the turbo has been mounted under the engine directly to the catalytic converters. Everything was also beefed-up to withstand the higher pressures of direct-injection diesel power.
Transmission Talk
A five-speed manual transmission was designed specifically for use with the diesel in Europe, but is not likely to be offered in North America. Rather, the U.S. must wait for an automatic transmission that is under development; it will likely be the only option on this side of the ocean. Europe will also get the automatic transmission as an option when it is ready in about two years, says Hirofumi Senoo, Fuji Heavy Industries Limited’s general manager of the Subaru Test and Development Center in Europe.
Senoo says that Subaru weighed whether this first boxer turbo-diesel should mate to a currently available six-speed manual, but using the six would have added 22 to 33 pounds with a resultant penalty in reduced fuel efficiency and agility, so the five was developed. A new six-speed that weighs the same as the five-speed will be available at the end of the year, Senoo tells Car and Driver in an interview at a press drive for the diesel engine.
U.S. Emissions Controls Aren’t Finalized
Meeting U.S. diesel emissions standards will be difficult, Subaru admits, especially while maintaining enough power to satisfy American consumers. While the new boxer diesel meets Euro4 regulations, it is not currently 50-state compliant. Senoo says Subaru is still grappling with which form of NOx after-treatment to adopt.
There also is the question as to how much demand there is for diesels in the U.S. Even if Americans were to clamor for it today, Senoo says it would take two more years of development with the whole team shifting focus to the project.
A North American diesel also must be able to withstand weather extremes (the engine has been tested in Sweden and Granada), and cost is always an issue, the officials say. Pricing for the European models will be released March 4 in Geneva.
Diesel Won’t Be Sold In Japan Yet, Either
The lack of a diesel has hurt Subaru sales in Europe, where the automaker has less than a one-percent share. The Japanese automaker would love to double its sales, but executives say that might be too ambitious.
Introducing the diesel on volume models—the Legacy and Outback—is the first step. Senoo says the engine could launch in the Forester and base Impreza in Europe as early as mid-year. He says a decision has not been made on putting a diesel in the WRX or STI, as maintaining their performance levels is key. Both would require the diesel to have more power, he says, and that is not easy to do.
Japan also has been slow to adopt diesels, where the engines account for less than one percent of the market. If the boxer diesel is offered for sale in Japan, it likely would be after the North American launch, Senoo says. Other future markets being considered include Russia.
Subaru introduced its first boxer engine 43 years ago, pairing it eight years later with its symmetrical AWD system. Work on the boxer diesel began after the introduction of the current-generation gasoline boxer engine at the end of 2004, and work on the Euro version of the diesel was completed at the end of 2007, Senoo says. The new diesel is built in Japan.
The plan is to keep the technology exclusive to Subaru, Senoo says.
2008 Subaru Legacy and Outback Go Diesel - Car News - Car and Driver January 2008
M
It’s a world first: a boxer turbo-diesel in a passenger car. Subaru has announced that a 2.0-liter four-cylinder diesel engine will be offered in the European versions of the 2008 Subaru Legacy and Outback beginning in March, following its debut at the Geneva auto show.
But the boxer diesel will be two or three years old when it becomes available in the U.S., Subaru engineers tell us. The Legacy, Outback, and Forester are likely candidates for diesel power in North America.
The concept is intriguing: a horizontally opposed diesel engine and Subaru’s symmetrical all-wheel-drive system, both squeezed into vehicles with restricted amounts of space—there’s no room for the package to take up any extra width or length. Compared to the 2.0-liter gasoline-fired four in Subaru’s stable—but not available in the U.S.—the diesel has a decreased bore, an increased stroke, and the turbo has been mounted under the engine directly to the catalytic converters. Everything was also beefed-up to withstand the higher pressures of direct-injection diesel power.
Transmission Talk
A five-speed manual transmission was designed specifically for use with the diesel in Europe, but is not likely to be offered in North America. Rather, the U.S. must wait for an automatic transmission that is under development; it will likely be the only option on this side of the ocean. Europe will also get the automatic transmission as an option when it is ready in about two years, says Hirofumi Senoo, Fuji Heavy Industries Limited’s general manager of the Subaru Test and Development Center in Europe.
Senoo says that Subaru weighed whether this first boxer turbo-diesel should mate to a currently available six-speed manual, but using the six would have added 22 to 33 pounds with a resultant penalty in reduced fuel efficiency and agility, so the five was developed. A new six-speed that weighs the same as the five-speed will be available at the end of the year, Senoo tells Car and Driver in an interview at a press drive for the diesel engine.
U.S. Emissions Controls Aren’t Finalized
Meeting U.S. diesel emissions standards will be difficult, Subaru admits, especially while maintaining enough power to satisfy American consumers. While the new boxer diesel meets Euro4 regulations, it is not currently 50-state compliant. Senoo says Subaru is still grappling with which form of NOx after-treatment to adopt.
There also is the question as to how much demand there is for diesels in the U.S. Even if Americans were to clamor for it today, Senoo says it would take two more years of development with the whole team shifting focus to the project.
A North American diesel also must be able to withstand weather extremes (the engine has been tested in Sweden and Granada), and cost is always an issue, the officials say. Pricing for the European models will be released March 4 in Geneva.
Diesel Won’t Be Sold In Japan Yet, Either
The lack of a diesel has hurt Subaru sales in Europe, where the automaker has less than a one-percent share. The Japanese automaker would love to double its sales, but executives say that might be too ambitious.
Introducing the diesel on volume models—the Legacy and Outback—is the first step. Senoo says the engine could launch in the Forester and base Impreza in Europe as early as mid-year. He says a decision has not been made on putting a diesel in the WRX or STI, as maintaining their performance levels is key. Both would require the diesel to have more power, he says, and that is not easy to do.
Japan also has been slow to adopt diesels, where the engines account for less than one percent of the market. If the boxer diesel is offered for sale in Japan, it likely would be after the North American launch, Senoo says. Other future markets being considered include Russia.
Subaru introduced its first boxer engine 43 years ago, pairing it eight years later with its symmetrical AWD system. Work on the boxer diesel began after the introduction of the current-generation gasoline boxer engine at the end of 2004, and work on the Euro version of the diesel was completed at the end of 2007, Senoo says. The new diesel is built in Japan.
The plan is to keep the technology exclusive to Subaru, Senoo says.
2008 Subaru Legacy and Outback Go Diesel - Car News - Car and Driver January 2008
M
