206 EV Miles On A Single Charge With A SIMple Solution
“The biggest problem” that faces widespread adoption of electric vehicles, “is striking a balance between performance and price.” The man who said that, Hiroshi Shimizu, thinks he has the solution to this problem. It is not generous subsidies. It is not miracle batteries. It is a technology his company has been developing over many years: In-wheel electric motors. Shimizu’s company , “SIM-Drive Corp. a Keio University-linked venture company, on Wednesday unveiled a prototype of its SIM-LEI electric vehicle that can travel up to 333 kilometers (206 miles) on a single battery charge,” writes Japan’s Jiji Press.
The “LEI” has nothing to do with Hawaiian flower necklaces. It stands for Leading Efficiency In-Wheel motor, says the Kawasaki-based company. Powered by a 24.5 kWh battery, pretty much the same as the Nissan Leaf, the 4-seater achieved “333km of range per charge by JC-08 mode, which represents general urban traffic condition in Japan,” says the company. Unusual is the acceleration: 4.8 seconds for 0 to 100 km/h, not quite a Veyron, but better that a Porsche 993 Carrera RS 3.8.
SIM’s in-wheel engines can be retrofitted to existing cars, an operation that should be as simple as changing tires (it probably won’t be.) For purpose-built cars, the in-wheel motors allow for a simple body structure, a lot of space, and stable running.
I know, by now you are racking your brain: “Hiroshi Shimizu, Hiroshi Shimizu, didn’t I hear that name before?” You did. He’s the man behind the 8-wheeled 370 km/h (230 mph) Eliica that also used SIM-drive electric hub motors. Keio is a Tokyo elite university. Hiroshi Shimizu is a professor at the school.
(Hold your comments of the design of the car. SIM intends to sell the technology, not the body.)
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I believe Bill Lear's last project in the 1970s was to put in-wheel motors on a bus. He thought a small diesel motor tuned for maximum efficiency matched to a bank of batteries would run a bus with much greater fuel efficiency than a conventional drivetrain. He ran into huge problems and died before those problems were solved. His heirs then pulled the plug on the project. I know one problem was durability of the in-wheel motor setup he was using, but there were other problems. Does anyone know or have heard heard of the other technical glitches Lear ran into? It was my understanding that with Lear's track record, his efforts were being closely watched, especially by GM.
Hrm, I was under the impression that the typical ICE car has ~20% drivetrain losses, and that's with a torque converter, big transmission with loads of viscous drag and friction, differential and halfshafts, each with 2 cv-joints. I have a hard time seeing a car like the leaf or the volt having more than 15% drive-train loss, so doubling the range of a leaf seems like it'd take a lot more than just drive-train efficiency increase.