Corvette ZR1KEY POINTS:
UPDATE: Just to prove that it's got the goods, GM has released a video of its new supercharged Corvette stretching its legs to a massive 205mph (330km/h) top speed.
At a time when car makers are showing off every imaginable fuel-saving gizmo, General Motors does the math on the 6.2-litre V8 engine in its new Chevrolet Corvette ZR1 and comes up with more oomph than it expected.
The company's powertrain gurus found that the LS9 engine cranks out 476kW (638bhp) - 20 horsepower more than the estimates they made when GM took the covers off the ZR1 before Christmas.
Simply, the engine is rated at 76kW (103bhp) per litre of displacement or 1.7bhp per cubic inch (6.2 litres is equal to 376 cubic inches).
All that power will push the Corvette ZR1 to a top speed of more than 322km/h, says GM. And torque? The revised official figure is now 810Nm.
The key to power and torque is a Roots-type supercharger with four-lobe rotors that sits atop the LS9 engine. A liquid-to-air intercooler is integrated into the supercharger's housing.
The engine will be hand-built at GM's Performance Build Centre in suburban Detroit, the same plant that hand-builds the LS7 V8 used in the Corvette Z06.
The red-blooded Corvette has been one of the stars at recent US motor shows, where carmakers have highlighted the greening of the car business.
Fuel-saving devices on display included hybrid electric, plug-in electric, fuel cell, diesel and direct petrol injection technology.
But for every energy miser there are American muscle cars like the Cadillac CTS-V, Dodge Challenger SRT8, Chevrolet Camaro and the usual go-fast offerings from Ferrari, Maserati and Lamborghini.
The line-up shows an industry furiously exploring ways to let customers enjoy traditional big, roomy and powerful offerings while reducing future fuel consumption.
Some in the industry fear technology could sap the fun had from driving.
Others say sales of high-priced performance vehicles like the Corvette ZR1 can help pay for future development.
"You can't take all the fun out of owning a car," said Joe Barker, senior manager of North American sales forecasting at market researcher CSM Worldwide. "There is some enjoyment that should come out of car ownership."
That show cars should fall at opposite ends of the performance and economy spectrums should come as no surprise, says Barker.
"It pretty much shows that Americans have mixed feelings when it comes to the car and the environment," he said.
"The love of horsepower is deep-rooted, yet high fuel prices and environmental concerns have Americans looking at efficiency.
"They want to do what's responsible environmentally."
