Over the past few days, there have been a lot of rumors flying across the Internet that Toyota will be resurrecting their Supra sports car in the guise of a hybrid performance vehicle. The company has been flirting with the idea of a hybrid sports car for a few years now, and they have shown off their FT-HS Concept Car a few times, offering a glimpse of what the next Supra could look like. So, in anticipation of an actual hybrid sports car hitting the market at non-boutique dealer prices, let’s look at the HT-FS concept.
The HT-FS uses a variant of Toyota’s Hybrid Synergy Drive, the hybrid drivetrain found on all of their, and the Lexus brand’s, hybrids. When the HT-FS debuted in 2007, Toyota had already created a new sporting variant of their hybrid system, which indicates that the company is fairly serious about the prospects of hybrid sports cars. The electric components would be mated to Toyota’s ubiquitous 3.5-liter V6 engine for a combined output in the neighborhood of 400 horsepower.
What would make a hybrid sports car a truly intriguing vehicle is the unique torque characteristics of electric motors. In a traditional internal combustion engine, there are areas of peak performance called “power bands.” So, for example, an engine’s peak torque power band could be from 2,000-4,500 RPM, but running the engine at RPMs outside that band would result in less than optimal power. The same is true for horsepower. What makes electric motors so intriguing is that their torque output is exactly the same from 1 RPM to their redline. Also, that torque is usually pretty high, with some hybrid models able to crank out 400 lb-ft of torque. Putting this power into a sports car would pay huge dividends on acceleration. The electric motors would rocket the car off the line, while the gasoling engine would take car of the high-speed cruising.
The issue with that, however, is that it uses a lot of electrical power, which is one of the reasons that you don’t see any hybrid sports cars on the market right now. Yes, the torque properties can make for some incredible acceleration, but the amount of battery weight that would be added to the vehicle to handle such extreme power usage would limit that vehicle’s handling abilities. But there is hope for future hybrid sports cars in the form of a new battery material called lithium-ion.
Current hybrid vehicles are equipped with a nickel metal hydride battery pack which, for the cost, does an adequate job. However, over the past few years, engineering companies have been experimenting with lithium ion battery setups. That name may sound familiar, as lithium ion packs are found in many cell phones, laptop computers, MP3 players, etc. However, scaling them up to power a car, and making them hold a standard charge over years, has been an issue. The benefits of lithium ion over nickel metal hydride is that they hold more power in a smaller package. A rough comparison would be that a 3-pound lithium ion pack would hold as much if not more power than a 5-pound nickel metal hydride pack.
And that brings us back to the FT-HS Concept and the possible revival of the Toyota Supra in hybrid sports car form. With the new lithium ion battery packs that are being developed, the car would be able to pack sufficient electrical charge without being hugely weighed down. Also, by properly positioning that pack, you’d be able to lower the car’s center of gravity to help increase handling.
The steady torque output of electric motors makes a hybrid sports car a tantalizing proposition, but the final package depends on a few things: first, the car has to be fun. What’s the point in buying a sports car if it drives like a Prius? Second, it has to have good mileage. If efficiency is sacrificed for the sake of performance, then the car will get lost in the shuffle. Why pay the extra money for all that hybrid technology if you don’t get the hybrid fuel benefits? Third, and last, the car has to be affordable. There are cars like the Tesla Roadster that are electric sports cars, but their production is so limited and the price so high that they are out of reach of 80-90% of the population. Toyota has the infrastructure and the know-how to create a true hybrid sportts car for the average person, not the rich collector, and that could be a huge game-changer.