Earlier this year Volkswagen announced production of its 261 mpg hyper-efficient XL1, but with an estimated $145,000 price tag it’s unlikely the hybrid will become a common fixture on most streets. The company’s Twin Up! hybrid concept, which made its debut at the Tokyo Motor Show yesterday, could however become a more reasonable option for the masses.

Cute as an inner-city button, Volkswagen’s new Twin Up! shares the same hybrid power configuration as the XL1, but without the sticker shock. By virtue a carbon fiber body and chassis, a drag coefficient of 0.30 Cd and a 2-cylinder, 800 cc diesel engine that works in partnership with a 35 kW electric motor, Volkswagen says the 2657 lb (1205 kg) car can make an astounding 214 mpg (1.09 L/100km). These figures would make the 1 liter Twin Up! the most efficient production car on the planet, and not too far behind the XL1 in terms of mileage bragging rights.

Unsurprisingly, performance figures of the Twin Up! aren't quite at supercar level, but they are definitely workable for an urban commuter. Volkswagen reports 0-100 km/h (62 mph) times of 15.7 seconds and a top speed of 140 km/h (87 mph) in hybrid mode. In electric mode only the Twin Up! has a top speed of 125 km/h (77 mph).

Volkswagen has chosen to go with a 7-speed DSG gearbox and with the 8.6 kWh battery and 33 liter gas tank mounted behind the rear seat, the concept is reported to provide a range of 50 km (30 miles) when running on electric power only. Total power output with both engines engaged is 74 horsepower and peak torque is 157 lb.ft (215 Nm).

The Twin Up! Hybrid system is designed so that the driver has control over when and where the electric is engaged, and when the diesel can come back into the equation via a “pulse start” system. This system is designed to seamlessly restart the diesel and bring it up to speed, thus avoiding any jolts upon engagement. Twin Up! uses regenerative braking to recharge the battery but also relies on “load point shifting” when running the TDI, which according to Volkswagen improves engine efficiency and feeds excess energy back into the charging system.

Inside, the tiny four-seater is decked out in Volkswagen’s “Ceramic” color scheme and features a user-configurable home screen designed specifically for the car. A dual-climate control system is mounted mid-dash that also shows air quality, temperature, energy efficiency and statistics for both drive systems.

While this is clearly a car designed with a high-volume production in mind, there's no word yet on when/if Volkswagen will bring the Twin Up! to production, or on what it will cost.

Source: Volkswagen