Three years ago, we first heard about the Mute electric concept car. Created via a collaboration between 20 departments at the Technische Universitaet Muenchen (TUM), it was designed chiefly to be efficient, inexpensive and safe. A project funded by the German Federal Ministry for Education and Research followed, in which a consortium of over a dozen companies (including TUM, Daimler and BMW) set about designing a Mute-based city car known as the Visio.M. That two-seater car is now complete, and is being revealed to the public for the first time this week.
Even though the Visio.M has just a 15-kW (20-hp) electric motor, the car still has a top speed of 120 km/h (75 mph) and a range of about 160 km (99 miles) with two passengers and luggage. That's actually better than the Mute's 100 km (62-mile) range, although that car has a more modest 10-kWh battery – speaking of which, the Visio.M's 13.5-kWh lithium-ion battery pack can be charged from a 230-volt socket, in a claimed three to four hours.
So, how is all that pulled off? Well, first of all, the Visio.M is light. Including its 85-kg (187-lb) battery, the car's total weight is 535 kg (1,179 lb). This is just 35 kg (77 lb) more than the Mute, although it's a full 135 kg (298 lb) over the project partners' original goal of 400 kg (882 lb). By contrast, though, the electric version of the diminutive Smart fortwo coupe tips the scales at 900 kg (1,984 lb).
One of the reasons for the Visio.M's light weight is the use of carbon fiber-reinforced plastic, along with aluminum, in the passenger compartment and roof frame. Additionally, all of the windows are made from polycarbonate. According to TUM, the material is half the weight of glass, but is just as durable thanks to a scratch- and weathering-resistant coating. The chassis, steering and transmission also incorporate a lightweight design.
Other efficiency-boosting features include an aerodynamic body, with a coefficient of drag of 0.24 and frontal area of 1.69 square meters (18.19 sq ft); tires optimized for low rolling resistance; and a torque vectoring system that evenly distributes both braking and driving forces between the rear wheels, allowing up to twice as much energy to be recovered when braking than would otherwise be possible.
Additionally, heat generated by the running of the car is recovered for use in heating the cabin, plus a carbon-neutral ethanol-powered heater is on hand for use in particularly cold climates – that heater does not draw power from the battery. On hot days, electrothermal converters in the cooling aggregate and seats help cool things down without the use of coolant fluids.
Safety-wise, the Visio.M packs some other interesting features. Among these is a 360-degree radar- and camera-based traffic-monitoring system, which reportedly identifies collisions moments before they happen. This works in conjunction with two-point belts, that are worn by passengers as part of their regular seat belt. When a side impact is about to occur, the belt pulls the passenger on that side in toward the center of the cabin, away from the point of impact. At the same time, the side airbags deploy, as does one between the driver and passenger, to keep them from slamming into one another.
The Visio.M is on display Oct. 21st thru 23rd at the eCarTec trade show in Munich. There's no word on eventual commercial availability, although TUM has stated that "The total cost of ownership, including initial investment and operating costs, will be lower than that of a comparable combustion engine car."
Source: TUM (German)
