Sports Cars Power Up

The Audi TT Quattro Roadster is a stylish two-seater that is unfashionably heavy and propelled by an engine with the least piston displacement. Still, the TT is arguably the most sophisticated engineering effort, with a turbocharged and intercooled engine and all-wheel drive.



Going in, the Corvette had the clear power edge. Chevrolet calls the Z06 the best-performing Corvette ever. The titanium exhaust system, thinner glass, and lighter tires save weight, though this brings some drawbacks. The center of gravity shifts slightly forward, which along with the long-for-a-sports-car (104.5-inch) wheelbase aggravates the problem of delivering 385 horsepower to ground through the rear tires. The trick is just the right amount of rpm before aggressively engaging the clutch. Get it right and the back of your head kisses the seatback as tires scratch the pavement for purchase and you blast by 60 mph in 4.7 seconds.



The others posed little threat to the Corvette's raw acceleration, even though the Porsche and the Toyota are notably lighter. The Boxster came closest at 5.9 seconds.



Zero-to-60 runs rapidly separate the quick from the lame, but top-gear-passing statistics tell another revealing story. How could the speedy Corvette be topped by the half-its-price Toyota? Turns out that the six-speed-equipped Corvette uses extra-tall gearing to avoid being branded a gas-guzzler by the federal government. The five-speed-equipped Toyota is geared to maintain engine rpm at all times to fully exploit its modest power.



In the case of the Audi TT, the good and bad aspects of the turbocharger are readily apparent. The exhaust-driven turbo isn't fully up to speed during 30- to 50-mph bursts, where this car's acceleration is distinctly off pace. But by 50 mph, there's sufficient exhaust-gas flow to help pressurize the engine's intake manifold, so the engine hits stride and hustles the TT into the lead. All this makes for far different sensations when the throttle's floored. Gear ratios in the Porsche and the Toyota keep their engines perpetually primed and ready, albeit at some noise and fuel-efficiency penalty. In the Audi and the Corvette,
you need to use the lower three gears for accelerating, the three taller ratios for quiet, high-mileage cruising.