The Legacy became the first model with the BOXER DIESEL. The Legacy was chosen since it was deemed most likely to appeal to European drivers owing to its stress on quietness and high performance, which were perfectly complemented by the BOXER DIESEL. The Legacy has also been recognized in Europe as a well built, quality car.
Legacy test vehicles were sent to Europe for evaluation, going through stringent tests in the high temperatures and high altitudes around Granada, Spain, as well as assessments for cold weather driving in Scandinavia and areas close to the North Pole. Each of 10 Legacy vehicles ran 100,000 km—a total of more than one million kilometers under a diverse set of conditions.
Throughout the rigorous tests, what the engineers appreciated most was the intrinsic superiority of the boxer configuration. Kenji Harima, Manager of the Engine Design Department remarked, “Advantages such as the quietness of the BOXER DIESEL also benefit the Legacy. The vehicle did not have to go through major remodeling to accommodate the diesel engine. Other manufactures uses the same platform for both gasoline and diesel engines, but they often have to modify the gasoline model by enlarging its rubber engine mount and other insulating components or by entirely enveloping the engine with insulators to reduce noise. The BOXER DIESEL has made it easy to convert the gasoline-based Legacy into the diesel-based model.”
Although a thicker toe board was employed and some insulators were added to the engine compartment, the modifications to the diesel Legacy were not extensive, thanks to the low vibration and low noise inherent in the BOXER DIESEL. In the speed range between 1000 rpm and 3000 rpm, low noise levels are primarily attributable to the rigid structure of the drivetrain unit of the Subaru AWD configuration. Between 1000 and 4000 rpm, the BOXER engine layout is the main contributor to low noise levels. At high speeds, between 3000 and 4000 rpm, the rigid crankshaft inside the BOXER DIESEL plays a key role in reduced noise levels. Compared to 4 cylinder inline diesel engines, the BOXER DIESEL affords quiet operation at all ranges of engine rotations.
On the characteristics of the BOXER DIESEL, Maeda adds, “Without balancer shafts, the BOXER DIESEL provides the driver with a direct feel for surging engine rotations. When stepping on the accelerator, the driver feels quick engine response that no other diesel engine can offer. For example, the engine reacts superbly in acceleration from 80 km/hr to 120 km/hr on highways.”
Designed in the pursuit of compactness, the BOXER DIESEL also excels in stability and supple handling. When going around a curve, the Legacy with the BOXER DIESEL is more effective than the Legacy 2.0-L nonaspirated gasoline model at countering centripetal acceleration, which prevents roll movement.
During a recent test drive of the Legacy with the BOXER DIESEL engine in Malaga, Spain, journalists offered many accolades: the BOXER DIESEL provides extreamly sporty feeling and feels like driving a gasoline vehicle; it’s a revolutionary diesel engine; one can identify the manufacture of this vehicle “Subaru” right after you drive and the BOXER DIESEL has a truly original character.
There is one more feature on the BOXER DIESEL that adds sophistication to this new engine. When diesel engines stall because of their high torque output, even at low engine speeds, passengers in the car experience an unpleasant jolt. By controlling fuel injection, the BOXER DIESEL prevents this big jolt when the vehicle reaches the stall limit, and stops the engine quietly. This tuning further represents Subaru’s dedication to quality and attention to detail.
