Toyota Debut's Prius GT Prototype at Goodwood Festival of Speed

What makes the GT different from any regular Prius is that it has been tuned to show how Toyota's Hybrid Synergy Drive

For the GT version, Toyota has juiced up both the gasoline and electric engines. (Photo: Toyota Canada)

powertrain can deliver sports car-like performance. The primary gasoline motor, a 1.5 liter direct-injection inline-four, has been replaced with the motor that's normally fitted to the European-only Yaris T-Sport - essentially the same motor as fitted to our Echo Hatchback. The engine is the same size at 1.5 liters, however the 99 horsepower rating is a 29 percent power increase over the stock 77 horsepower Prius engine. The sport-tuned I-4 is also livelier, with eager-to-rev characteristics and a higher redline.

On the electrical side of the equation, Toyota has juiced up from 500 to 550 volts, allowing a greater flow of electricity. More happy electrons running through the car's power grid means that a larger electric motor can be installed which makes for a happier driver. The upgraded electric motor is good for 46 horsepower,

The upgraded Hybrid Synergy Drive system achieves 145 horsepower, which approaches the 100 horsepower per liter output. (Photo: Toyota Canada)

which is a gain of 12 horsepower over the stock unit. The regular battery has been replaced with a more powerful cell capable of supplying extra juice to the larger electric motor. The electric motor's torque curve is as broad as they come, stretching from 0 through to 12,000 rpm. It gives a whole new meaning to on-demand torque.

Put two and two together and it's rather apparent that the Prius GT has stretched the limits of technology on both the gasoline and electric sides. Altogether the Hybrid Synergy Drive system achieves 145 horsepower, which approaches the 100 horsepower per liter output, impressive by any standards let alone that of a hybrid.