The racy hatchback design echoes that of the original quattro and especially aims for the short-wheelbase quattro Sport of 1984 but with much-improved balance because the rear overhang is reduced to be proportional to the car’s length.

Like those early quattro models, the quattro concept relies on a turbocharged I5 powerplant, reflecting today’s similar interest in balancing power with efficiency.  The engine is derived from the 340-hp (254-kW) 2.5-L five-cylinder revival engine that appeared in the TT RS but pumped up to 408 hp (304 kW). The quattro concept’s 354 lb·ft (480 N·m) of peak torque is available from 1600 to 5300 rpm. This power contributes to the car’s ability to launch to 100 km/h (62 mph) in just 3.9 s.

The compact engine measures only 19.5 in (495 mm) long, making it suitable for longitudinal installation (as in the original car) in the quattro without contributing to excessive front overhang or compromising the car’s pedestrian-impact-protection properties. The compactness also contributes to the engine’s low mass, at just 403 lb (183 kg), which in turn contributes to the car’s minimal curb mass of just 2886 lb (1309 kg).

Downstream of the engine is a six-speed manual transmission, another tribute to the past in an era when Audi is known for its automated dual-clutch transmissions. The quattro features a center differential using a self-locking crown gear design that contributes to a 6.6-lb (3.0-kg) mass savings in the drivetrain.

The differential normally sends 60% of the torque to the rear differential but can increase that depending on traction to as much as 85%. Similarly, if the rear wheels are slipping, it can shift as much as 70% of torque to the front differential. This broad range of torque distribution vastly exceeds that of quattro all-wheel-drive systems previously.

The rear differential has active torque distribution with a superposition gear that spins 10% faster than the driveshaft. A wet multiplate clutch operated by an electrohydraulic actuator lets the differential send that higher speed to the outside rear wheel when cornering and simultaneously drawing torque away from the inside wheel, helping push the car around corners.

An aluminum body structure is the main reason for the light overall weight. The quattro’s chassis is constructed of extruded sections, die-castings, and aluminum sheets, while bolt-on parts such as the hood, hatch, bumpers, spoiler, and other small bits are carbon fiber. The resulting body-in-white totals a mere 351 lb (159 kg), which the company estimates would be 50% higher if the car were made entirely of steel. It is even 440 lb (200 kg) lighter than Audi’s aluminum-intensive TT RS.

The concept is shorter than the RS 5 coupe, with the wheelbase trimmed 150 mm (5.9 in) and 200 mm (7.9 in) whacked off the rear overhang to preserve the car’s proportions. The roof is also 40 mm (1.6 in) lower for the same reason.

The quattro’s weight/power ratio of 9.48 lb/hp (5.76 kg/kW) is on par with that of the company’s R8 V10 supercar, which promises outstanding performance for the hatchback.

Some of the weight savings came from the interior, where engineers cut the weight of the quattro’s seats by about 40% compared to production units. The concept’s seats weigh just 40 lb (18 kg) apiece and are equipped with either three- or four-point belts.

Audi made no announcements regarding production plans, but Volkswagen Group CEO Martin Winterkorn did note that an improving car market makes a fun model like the quattro concept more likely. “In the auto industry, signs again look good,” he said.