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All electric cars tend to be rather quiet, but this one is flat out MUTE. That's the name of the new lightweight EV designed by scientists from Technische Universität München (Munich Technical University).

The students hope to create an electric vehicle that's more affordable, but with skinny, low rolling resistance tires and exceptionally low weight (500kg), MUTE's dune buggy-esque design seems more like a competitor for a high mileage competition than a car that's intended to be a daily drive. However, MUTE uses some sophisticated active suspension that incorporates torque vectoring and electronic stability control to keep the vehicle's handling predictable and safe under different speeds and passenger loads.

The Munich team will be bringing the MUTE to the Frankfurt Auto Show this fall, and hopes to beat the curse that has thwarted so many would-be EV makers by bringing the MUTE to market in under five years. The race is on. A full press release is available after the jump.


[Source: Science Daily Photo: TU Muenchen]
Show full PR text
MUTE prototype displays excellent driving dynamics

Technische Universitaet Muenchen will be presenting its new electric vehicle concept "MUTE" at the international motor show in Frankfurt from 15 to 25 September. Following months of preliminary work on computer simulations, the first completed prototype showed in driving tests that MUTE possesses excellent driving properties – not only in theory, but also in practice.

For the first time, a handful of curious bystanders had the opportunity to see TU Muenchen's new electric vehicle in test runs. But the final design of MUTE remained shrouded; it will first be revealed at the IAA in Frankfurt (15 – 25 September 2011, hall 4, C 23). The MUTE prototype is built so that it has the same driving dynamics as the final vehicle.

The first test drives speak for the ingenious construction of the vehicle, which was tried and tested in numerous computer simulations. Particularly noticeable are MUTE's narrow tires. They minimize rolling friction, thereby extending the range of the vehicle. To ensure good cornering ability in spite of the narrow tires (115/70R16), the lateral dynamics of the vehicle were optimized by adjusting suspension, damping and axle kinematics. As a result the MUTE prototype completed the ISO Lane Change test better than a most conventional medium-sized automobiles.

A further important feature is the low weight of the vehicle. MUTE has a curb weight of only 400 kg, with another 100 kg for the batteries. "Low weight is essential for electric vehicles," says Professor Markus Lienkamp from the Chair of Automotive Technology at TUM. "More weight requires higher battery capacity for the same range and thus generates significantly higher costs. More weight also means inferior dynamics for a given level of motor power. But what we are aiming at is an affordable car that is fun to drive."

MUTE's low curb weight means that the weight of passengers and baggage cannot be ignored, which is why the ratio between the spring force and the resulting contact patch load is chosen slightly progressive. This ensures that driving comfort remains the same for both light and heavy drivers, although using springs with linear characteristic. Approaching full load the spring force in the tire contact patch increases progressively, diminishing comfort slightly to allow for sufficient residual spring travel.

The results of the first test runs are also important for the design of the active torque vectoring differential. A small electric machine integrated in the differential serves to distribute the force evenly between the two back wheels. Especially when braking in curves, twice as much energy can be recouped than without torque vectoring. This ideal distribution of propulsive force between the two back wheels makes the car much more agile and safer. As a result the driver will hardly notice any reduction in lateral dynamics caused by the narrow width of the tires.
Whenever possible, MUTE brakes by using the electric motor as a generator. The recovered energy is then fed back into the battery. When more braking power is needed, the electronic stability control (ESC) also activates the disc brakes on the front wheels.

"MUTE achieves a high level of safety through ESC and torque vectoring," says Michael Graf, who designed the driving dynamics parameters and subsequently did the test drives. "MUTE falls into the top 25 percent of existing medium-sized vehicles when it comes to driving dynamics and is absolutely easy to handle." Even load reversal in curves does not impede safe handling of the vehicle – oversteering is easy to compensate. "Our practical tests show that MUTE outperforms theoretical forecasts," he adds proudly.
Source: Gas 2.0 (http://s.tt/12Ugb)


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    • 1 Second Ago
  • 19 Comments
      Ernie Dunbar
      • 3 Years Ago
      Actually, it looks to be competing with the GEM: http://www.gemcar.com/
      BipDBo
      • 3 Years Ago
      It looks like they eventually plan to give it some skin, some handsome skin. It will gain some weight with a body, but will be more aerodynamic. http://gas2.org/2011/07/24/new-budget-ev-coming-to-frankfurt/ The battery only weighs 100kg. Assuming that it is similar to the Leaf battery which is 24kw*hr at 300 kg, this battery will only be 8 kw*hr, giving it a range of maybe 50 miles. It sounds like this is less likely to be a successful production car and more likely to be a showcase / test mule for an impressive stability system and torque vectoring differential. I'd like to see how that thing works. This sounds like technology that could be sold to big auto companies.
        paulwesterberg
        • 3 Years Ago
        @BipDBo
        It depends, five years from now battery energy density should be high enough that a 100kg battery could push a small light vehicle like this around urban/suburban city streets for 100 miles. At full highway speed the range would probably be more limited, but that depends more on areodynamics.
        Dan Frederiksen
        • 3 Years Ago
        @BipDBo
        I trust the weight is including the body BidDBo.. : ) they say it's 10kWh battery and remember it weighs 500kg. not the 1700 like the Leaf does so it goes further pr Wh. they say it will go at least 100km. the low weight will likely mean its range in city driving is much higher. with high density laptop cells you can put more than 20kWh into 100kg which could be interesting in a marathon version. might give it 400km range in city driving.
        fly by wireless
        • 3 Months Ago
        @BipDBo
        If it only weighs, say, 600kg with those skinny tires then it should get around 65 or 80 MPC with an 8kwh battery.
      Chris M
      • 3 Years Ago
      I hope that's just a test platform, with a full body shell and doors to be added! Don't expect actual production, though, most university projects like this are for research, testing and education, universities are not set up for major manufacturing operations.
        budfox
        • 3 Months Ago
        @Chris M
        Ja, the car shown in the picture is obviously just a test platform. http://www.mute-automobile.de/en/special/home.html
          budfox
          • 3 Months Ago
          @budfox
          [url]http://www.mute-automobile.de/en/special/home.html[/url]
          budfox
          • 3 Months Ago
          @budfox
          darn.
      Peter
      • 3 Years Ago
      Gotta love the camouflage vinyl on a car that hasn't got (much) of a body -> they have chutzpah!
        Ryan
        • 3 Years Ago
        @Peter
        Are they planning to mass produce this? Why hide it? Or is it just practice for real world procedures... I wonder how far it can go with the reduced weight? Interesting concept, I just wish a major manufacturer would produce something like it.
          Marco Polo
          • 3 Years Ago
          @Ryan
          @ Ernie Dunbar, or possibly the Moon?;) But you are right, as a specialist off road vehicle, the lessons learned may prove valuable in conventional design. @ Dan Frederiksen; Would you? Would you really drive that on the highway? Oh, please do, it would be worth putting it in production, just to observe you in a freeway accident in such a vehicle! One squashed troll less, might be worth it! The original BMC Mini- Minor, was a brilliant little car. No question, it's bigger brother the 1100, was astonishingly revolutionary in design, but both vehicles were incredibly dangerous in any sort of road collision. That appears to be your "brilliant engineering advice" to manufacturers. Incredibly expensive vehicles, with no safety engineering. Even if a government was so irresponsible as to permit such an inherently unsafe vehicle on the road, the cost of insurance would be prohibitive. P/s (Sigh) Having been in a serious road accident, I wouldn't wish it on anyone, not even you!
          Marco Polo
          • 3 Years Ago
          @Ryan
          Where would you drive it?
          Dan Frederiksen
          • 3 Years Ago
          @Ryan
          Roads, Marco Polo. Roads
          Ernie Dunbar
          • 3 Years Ago
          @Ryan
          @Marco Polo: in the desert, obviously. :)
          Dan Frederiksen
          • 3 Years Ago
          @Ryan
          MP, as ll cars get lighter there is no disadvantage to being light
      paulwesterberg
      • 3 Years Ago
      It looks like it would be a blast to drive. It looks like it would be more of a fair weather car, I wouldn't trust such skinny tires on frozen snowy roads. I would rather have the motor in the front as I think the regenerative braking would be much more effective.
        • 3 Years Ago
        @paulwesterberg
        Narrow tires are an advantage on adverse road conditions ;-) That is why winter tires are narrower than summer tires... Apart from that: contact patch area per weight is the main factor - the same here as in a conventional car with 3 times the tire width. There is a lot of package, weight, cost reasons to go RWD. The car makes up for the disadvantage in stability during recuperation by using torque-vectoring. There should be close to no energetic disadvantage in real world driving compared to FWD German Source also available there in English: Graf, M.; Wiesbeck, F.; Lienkamp, M.: Fahrdynamikauslegung eines E-Fahrzeuges – Fahrwerks- und Torque-Vectoring-Entwicklung für das Fahrzeug MUTE, Automobiltechnische Zeitschrift, Cover Story ATZ 113 (2011) H.06 Regards, WiSi
      Dan Frederiksen
      • 3 Years Ago
      not bad. the weight is pretty good, so is the design and it seems like it has semi decent aerodynamics. I would probably emphasize aerodynamics even more though ala the EV1, Loremo, Sunrise but it's not bad. if they give it strong acceleration which is quite easy with only 500kg it could be good. they have a website http://www.mute-automobile.de/
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