FHI unveils an Intelligent Driving Enhancement System
April 14, 2006 Japanese industrial heavyweight Fuji Heavy Industries (FHI), the maker of Subaru automobiles, today announced the development of its SI-DRIVE (Subaru Intelligent Drive), an innovative driving enhancement system that provides optimal control of the powertrain unit and delivers driving pleasure under various traffic and road conditions. The company displayed a Legacy sedan 2.5GT equipped with the new system, at the New York International Automobile Show. The SI-DRIVE enables three distinctively different modes of engine power characteristics by regulating the engine control unit (ECU) as well as the transmission control unit (TCU) in the automatic transmission, and by fine-tuning the electronically controlled throttle. Intelligent mode ensures smooth, strong power output, yet facilitates city driving at low- to mid-speed range and contributes to greater fuel economy. The Sport mode is designed to deliver ideal power, faithful to the driver’s acceleration, and heightens enjoyable, sporty driving under a wide range of road conditions. The Sport Sharp mode further elevates sporty driving by accurately responding to the driver’s acceleration and boosting engine revolutions earlier than the Sport mode for a more powerful driving experience. The SI-DRIVE selector will be installed on the center console for the driver to choose from these three modes, which bring out very different driving experiences while driving the same car.
FHI has also developed a new interface to display SI-DRIVE performance, effectively communicating vehicle behavior and fuel economy to the driver. The instrumentation incorporates an ECO gauge that encourages mileage-conscious driving; a multi-information display that shows comprehensive information about the power characteristics of the driver-selected SI-DRIVE mode; and a Shift-up Indicator for the manual transmission model that advises the driver to shift up a gear. Together with the improvements in the powertrain design for greater fuel economy and the new mechanism for the optimal powertrain control, mileage information given on the multi-information display and ECO gauge have proven to positively influence drivers to drive more fuel-efficiently. FHI’s internal tests have indicated that a vehicle with the display driven in the Intelligent mode recorded 10%–better gas mileage compared to an equivalent model without these improvements and display.
The SI-DRIVE not only offers enhanced driving pleasure, but it also takes on the role of an intelligent device, promoting communications between a driver and a car. In addition to FHI’s core technology, the Symmetrical AWD (All-Wheel Drive) system, SI-DRIVE presents yet another technological triumph that further advances the company’s development philosophy to pursue ultimate driving pleasure under any circumstances and conditions. FHI plans to introduce the SI-DRIVE worldwide later this year in turbo-engine and 6-cylinder-engine Legacy series models.
Major features of the SI-DRIVE
Intelligent mode: Fuel consumption is lowered through maintaining effective control of engine torque output and by adjusting lock-up control in the automatic transmission, while ample power is smoothly output. The Intelligent mode ensures fuel economy, not only through optimal powertrain control but augmented by the ECO gauge that promotes fuel-efficient driving. Sport mode: Power output is designed to reflect the precise degree of accelerator pedal depression, even in a turbo engine model, as if the driver is experiencing normally-aspirated engine power output characteristics. This mode promises pleasurable driving with a variety of vehicle uses and under diverse road conditions.
Sport Sharp mode: Response to engine revolutions accurately reflects power output, from low to high revolutions, enabling sporty driving even on rugged and winding roads. In the automatic transmission model, gearshift timing is set at higher engine speeds for powerful drivability.
SI-DRIVE display components
SI-DRIVE selector: The selector dial facilitates the choice of mode by a driver. By pushing the dial, the Intelligent mode is set, while the Sport mode is activated by turning the dial to the left, and the Sport Sharp mode is engaged by turning it to the right. ECO gauge: The ECO gauge is located below the speedometer. The hand set in the gauge is a pendulum, and when fuel mileage goes above the average, the hand shifts to the right area. The average mileage is calculated by analyzing past driving patterns. Multi-information display: In addition to average and actual mileage and other fuel economy information, the display shows simplified torque curve at the driver-set mode and levels of throttle valve opening. Shift-up Indicator: Located in the tachometer, the indicator blinks to encourage a driver to shift up a gear to save fuel when engine revolutions reach a certain level during acceleration.
First offered for 2006 in a limited edition production run of 500 units, the Legacy 2.5 GT spec.B returns as a regular production model for 2007, featuring a host of performance and interior enhancements. In addition to the new SI-Drive system, the 2007 spec.B also gains a modified version of the 6-speed manual transmission from the Impreza WRX STI, plus the advanced Vehicle Dynamics Control (VDC) system and a Tire Pressure Monitoring System. The 6-speed transmission is tailored to suit the spec.B’s refined driving characteristics and features unique gear ratios and a smoother shifting operation than the version used in the WRX STI.
Like all Subaru models, the 2007 Legacy 2.5 GT spec.B features Symmetrical All-Wheel Drive as standard equipment. The 2.5-liter intercooled turbo Boxer engine in the spec.B produces 243 horsepower @ 6,000 rpm and 241 lb.-ft. of peak torque @ 3,600 rpm. Subaru Active Valve Control System (AVCS) variable valve timing optimizes power at all engine speeds. The new Subaru SI-Drive system will also be standard on all Legacy 2.5 GT Limited and Outback 2.5 XT Limited models for 2007 (all are powered by the same engine). In its 2006 form, the Legacy 2.5 GT spec.B has already shown its taillights to a number of premium brand sport sedans. The 2007 model carries forward the Bilstein Sport Suspension with inverted front struts, 18-inch aluminum-alloy wheels and high-performance tires.
Once again, the Legacy 2.5 GT spec.B features an exclusive interior design, for 2007 featuring Charcoal Gray leather-trimmed upholstery with Dusk Blue Alcantara inserts.
A new standard SRS WOW audio system brings a new sonic performance and quality to the Legacy line, plus MP3 and Windows Media Audio (WMA) playback and an input jack for iPods and other portable audio devices. All Legacy and Outback audio systems for 2007 offer XM Satellite Radio capability.
SI-Drive: Three Engines in One The new SI-Drive system allows the driver to maximize engine performance, control and efficiency by choosing from among three selectable modes – “Intelligent” “Sport” and “Sport Sharp” – using a rotary dial on the center console. The SI-Drive controls the electronic throttle system’s response and fuel and ignition curves to modify engine torque characteristics, changing the performance character of the car in each mode. With Intelligent mode selected, the system reduces engine torque and maximum power and switches to a more relaxed throttle response curve. Intelligent mode is an ideal choice for smoother response while commuting in traffic, for example, where it can also help boost fuel efficiency by up to 10 percent. In addition, Intelligent mode’s more relaxed responses and lower torque output make it an ideal complement to the low-traction surface driving safety provided by the Subaru Symmetrical All-Wheel Drive System.
In “Sport” mode, the performance of the 2.5 GT spec.B (and other 2007 turbo Legacy and Outback models) is similar to the 2006 model, with quick throttle responses and powerful, linear acceleration. The linear acceleration characteristic of this versatile mode makes it ideal for driving on freeways and suburban streets or for climbing mountain roads. In “Sport Sharp” mode, SI-Drive modifies the engine’s electronic throttle mapping to deliver lightning quick throttle response and more power sooner. Delivering maximum driving enjoyment, this mode is ideal for tackling twisty roads and for merging or overtaking other vehicles on the highway with confidence.
On 2007 Legacy and Outback models equipped with the 5-speed automatic transmission (not available on Legacy 2.5 GT spec.B), SI-Drive also changes the transmission’s shift patterns. It will hold each gear longer through the rpm range and downshift more quickly under hard acceleration, depending on the mode selected.
The SI-Drive system includes instrument panel displays that allow the driver to monitor performance. The multi-information display located in the tachometer face – in addition to providing trip computer functions – denotes the selected SI-Drive mode and provides an active torque curve display.
When “Intelligent” mode is selected in vehicles with a manual transmission, a shift-up indicator blinks to signal the optimal shift point for maximum fuel efficiency.
Symmetrical All-Wheel Drive + Vehicle Dynamics Control
The 2007 Legacy 2.5 GT spec.B is equipped with one of the industry’s most effective combinations of all-weather handling technologies: Subaru Symmetrical All-Wheel Drive plus Vehicle Dynamics Control (VDC), a stability system that was previously available only on the B9 Tribeca SUV model and the top-line Outback.
Teamed with a manual transmission as in the Legacy 2.5 GT spec.B, Subaru Symmetrical All-Wheel Drive employs a viscous-coupling locking center differential with a normal 50:50 torque split. Slippage at the front or rear wheels will transfer more power to the opposite set. Vehicle Dynamics Control (VDC) is an advanced stability system that can help keep the vehicle going in the direction the driver is steering, especially in slippery road conditions. The system can be deactivated for conditions that require some wheel slippage, such as extricating the car from deep snow. New for 2007, a Torsen limited-slip rear differential helps to optimize traction at the rear wheels.
Exclusive Bilstein Sport Suspension
The exclusive Bilstein Sport Suspension equips the Legacy 2.5 GT spec.B model with performance-tuned shock absorbers for improved cornering response. Subaru replaced the MacPherson strut front suspension of other Legacy models with an inverted strut configuration similar to that in the rally-bred Impreza WRX STI, including aluminum-alloy lower control arms.
The multi-link rear suspension features aluminum-alloy rear arms and upper links in place of cast-iron pieces to reduce unsprung weight (and thereby enhance handling response). Finally, the 18-inch alloy wheels are fitted with 215/45 R18 Bridgestone Potenza RE050A summer performance tires. (The standard Legacy 2.5 GT Limited models feature 17-inch alloy wheels and all-season tires.)
A 4-wheel disc Anti-lock Brake System (ABS) with Electronic Brake-force Distribution (EBD) is standard on all Legacy models. The 2.5 GT Limited and 2.5 GT spec.B models employ larger brake rotors than other Legacy models, with ventilated rear discs in place of solid discs.
Distinct, Sophisticated Design – Outside and In
The Legacy 2.5 GT spec.B not only appeals to driving enthusiasts for its performance, but for its appearance that is both distinctive and “stealthy.” The Legacy 2.5 GT spec.B is quickly identified by its aerodynamic side ground-effects moldings with chrome trim. The road-hugging stance of the spec.B is further accentuated by the exclusive 18-inch wheels.
The Legacy 2.5 GT spec.B continues with its own exclusive interior, with the 2007 model featuring new Charcoal Gray leather-trimmed upholstery with Dusk Blue Alcantara inserts in place of the 2006 model’s Brick Red leather-trimmed upholstery.
The standard 8-way power driver’s seat gains a memory function for 2007, and the interior is further differentiated from the Legacy 2.5 GT Limited model by aluminum-alloy pedal covers, a 3-spoke MOMO leather-wrapped steering wheel with integrated audio controls and “spec.B” floor mats. The Subaru Navigation System remains standard on the spec.B model and available for all automatic transmission-equipped Legacy 2.5 GT Limited models.
Standard features shared with the 2.5 GT Limited Sedan include dual-zone automatic climate control, performance-design front seats, power moonroof, 4-stage heated front seats, a 4-way power passenger seat and heated exterior mirrors. In addition, all Legacy sedan models for 2007 gain a new standard 60/40 split fold-down rear seat with trunk pass-through to enhance cargo-carrying versatility.
All Legacy models for 2007 feature, as standard equipment, the Subaru Advanced Frontal Air Bag System, front seat side impact air bags, active front seat head restraints and side curtain air bags.