After already establishing the A4 as a class leader for fuel efficiency, roominess and power, Audi has expanded its engine options for 2009 to include a powerful new record setting TDI. To further demonstrate the cumulative result of utilizing as many current fuel saving measures as possible, Audi has also produced the “e” concept.
Central to the A4 concept is a 120 horsepower 2 liter turbo-diesel engine adopted from parent company Volkswagen. Audi engineers have managed to squeeze out even more fuel economy through through a variety of upgrades including softer springs on the intake valves, a new coolant-management system, and revamped its engine-control software. The diesel is coupled to a six-speed manual transmission that utilizes magnesium hardware to further reduce the concept’s weight. Like the start/stop systems developed by Volvo and Mazda, the “e” saves gas by implementing a system tht automatically shuts down and starts the engine when the vehicle would otherwise be idling. Similar to hybrid vehicles, a second battery is recharged through regenerative braking that powers the vehicles accessories. Other energy saving features of the “concept e” include low rolling-resistance tires, electric power steering and electrically-actuated rear brakes. The already typically svelte Audi is further aerodynamically enhanced by a smoothing out of the front fascia and body. The trunk lid with a restrained separating edge adds to the already excellent aerodynamics and the partially closed grid in the single-frame grille and sport-tuned suspension for optimized ride height also contribute to the excellent drag coefficient. Despite all of these seemingly miniscule changes from the standard A4, the concept achieves an amazing 58.95 mpg in combined city and highway driving while emitting only 105 grams of carbon dioxide per kilometer. This incredible gas mileage and not performance are certainly the highest priority with this concept, however. The sedan is only capable of reaching 60 mph in a ho-hum 10.7 seconds and tops out at 128 mph. To help promote responsible driving, Audi provides drivers with access to an in-vehicle display that offers up various recommendations to help facilitate fuel-saving driving habits. Audi has plans to expand its ‘e’ model line in the future and start putting many of these technologies into other production vehicles