When the Corvette Z06 was introduced this week at the Detroit Auto Show, GM announced that the Z06 was their fastest car ever when engineers tested it at the Milford Proving Grounds, Corvette chief engineer Tadge Juechter told reporters.

The 2015 Corvette Z06 shares an aluminum frame with its high-profile sister, the Corvette Stingray, but it's distinguished by an 6.2-liter "supercharged" V-8 mated with a custom-made eight-speed automatic transmission.

It's a fit-for-the-street race car boasting at least 625 horsepower, says Nathan Bomey, Detroit Free Press.

It also boasts a tremendous amount of "downforce," an engineering term describing a car's ability to hug the road when it barrels around corners. Most mass-market vehicles are exactly the opposite: they have too much lift when cornering.

"It's got more downforce than any vehicle General Motors has ever tested from any manufacturer," Juechter said. "We haven't tested them all, but we've tested quite a few of them."

Production of the Z06 will start "in earnest" in the first quarter of 2015 at GM's Bowling Green, Ky., Corvette assembly plant, Juechter said.

It will be offered with a seven-speed manual transmission, or with an eight-speed automatic. It's one of GM's first eight-speed transmissions. The first was mated to an uplevel version of the 2014 Cadillac CTS.

"This is an internally designed, all-new eight-speed transmission designed essentially to the requirements of this car," Juechter said.

GM also incorporates lessons learned in developing racing versions of previous Corvettes. For example, Juechter said the sixth-generation Corvette racecar influenced the forward-tilted radiator, the use of carbon fiber and the tires on the Corvette Stingray.

"We use racing to drive the street car to be better," Juechter said.

Like the Stingray, the Z06 engine has direct injection, cylinder deactivation technology and continuously variable valve timing. But it has 37% more horsepower and 40% more torque than the Stingray.

"It's a mosaic of different technologies," Juechter said.

Who's ready for a test drive?