Automotive

Mississippi State University squeezes 100 mpg out of hybrid Subaru BRZ

Mississippi State University s...
Mississippi State University has turned a regular Subaru BRZ into a lightweight hybrid
Mississippi State University has turned a regular Subaru BRZ into a lightweight hybrid
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Mississippi State University has turned a regular Subaru BRZ into a lightweight hybrid
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Mississippi State University has turned a regular Subaru BRZ into a lightweight hybrid

Researchers at Mississippi State University have taken a regular Subaru BRZ, ripped out the boxer engine and replaced it with a lightweight hybrid system to create what they call "the car of the future."

It might look like your average Subaru, but under the skin this BRZ has been given a thorough overhaul. The MSU team's cast magnesium subframe is 40 percent lighter than the stock unit, and offers a mounting point for the dual electric motors.

Drive comes from those electric motors at the rear, which draw their power from lightweight batteries that take advantage of proprietary cell cooling technology to work more efficiently. The battery pack from A123 Systems weighs just 374 lb (170 kg), which helps to keep the car's weight to 2,904 lb (1,317 kg) – or about 80 lb (36 kg) heavier than a petrol-only BRZ.

With 12.7 kWh, it's not going to challenge Tesla anytime soon, but it is enough for at least 50 miles (80 km) of all-electric running.

Why is the hybrid BRZ heavier than a petrol car? Because, in spite of the lighter subframe, MSU's car houses two electric motors, a battery and a petrol engine. That petrol engine is a two-cylinder, 850cc unit coupled with a 100 kW (134 hp) generator to act as a range extender when battery power is depleted.

According to its creators, the combination of petrol and battery power is enough to return an economy figure of more than 100 mpg (2.4 l/100km).

Beyond the hardware, there's a torque-vectoring system to enhance the BRZ's handling characteristics with eye-popping grip in tight corners, and control algorithms to recognize driver habits and predict what they're likely to do next.

The hybrid BRZ was shown this month at the Society of Automotive Engineers World Congress in Detroit.

A video explaining the car's technology is below.

Source: Mississippi State University

Bagley Car of the Future

7 comments
MichaelYoung
That's 100 m per US gallon, not Imperial, of course?
Jason Catterall
The battery pack weighs "just" 374lb? You can get a Zero electric motorcycle with a 13kWh battery and the whole thing, bike included weighs about that.
zr2s10
Subaru should just buy all the drawings from the school and sell these! If performance is good enough, and they don't overprice it, they could sell a ton of them, and they have very little engineering cost to recoup. Obviously crash testing, etc, will have to be done, but this is an excellent proof of concept for them to start with.
tyme2par4
So basically they dropped a BMW i3 powertrain into a BRZ. Nothing too special here...
habakak
I can say one thing for sure. This is NOT the car of the future. The car of the future (until the next revolution) will be an all electric vehicle. And they will be battery electric or hydrogen-electric.
Stephen Colbourne
They need to be more specific about the 100 mpg (2.4 l/100km). What is the mpg from when the battery is used up ? Probably nearer 20mpg I expect.
zr2s10
Even if you assume they ran 1 gallon of gas and used all 50 miles of electric range to reach that 100 mpg, that equates to 50 mpg gas only. The stock BRZ does not get that for sure. I'm also impressed by the torque vectoring. Extreme case; you could turn the car using just the electric motors. They've used that to their advantage to improve the handling over stock, on an already agile (although not extremely fast (stock)) car. Jalopnik has an article on this, and if they're impressed, you know they're on to something, lol