It is no surprise, given the minimalist aspirations, that Audi's two-seat eco-star at the Frankfurt motor show - the "urban concept study" electric vehicle - shows similarities with two other similar concepts also appearing at the show: Opel's two-seat EV and Volkswagen's singe-seat NILS. Similar to both Opel and VW efforts, the lightweight 480kg Audi measures 3.2 metres long, 1.7 metres wide and stands 1.2 metres tall. It is powered by a 90kg lithium-ion battery mounted transversely behind the seats. Two electric motors driving the rear wheels generate 15kW and 47Nm and drive through a single-speed transmission. Audi says the battery recharges in around 20 minutes with a 400-volt three-phase system, or in about one hour with a 230-volt household power outlet. It is said the concept study's range is around 73km and that it accelerates from zero to 100km/h in 16.9 seconds. Audi says the indicatively slow acceleration is partly offset by the smart step-off typical of an electric car. Top speed is governed to 100km/h. The car sits on 21-inch wheel shod with tyres measuring 125/60 up front and 145/50 at the rear. Body construction is largely carbon fibre reinforced polymer (CFRP) while the occupant cell is a mix of CFRP and an aluminium structure. At the back, a small luggage compartment "pulls out like a drawer." The F1-style suspension with near-horizontal struts up front is also made from a combination of CFRP and aluminium. Because the car is so light, the rack and pinion steering is unassisted. It has a turning circle of "less than nine metres." The Audi gets front and rear crumple zones, two airbags and a pedestrian-friendly system that can avoid collisions. Audi says the urban concept study has a sibling that wears a spyder-style body with a "flat window strip wrapping around the cockpit, and doors that opens upward at an angle."