DETROIT -- The 2006 Corvette Z06, the fastest 'Vette ever built, gets its speed from balsa wood.

OK, maybe that understates the value of its V-8 and light body, but when building a car that goes from 0 to 60 in 3.7 seconds, cutting weight is critical.

And balsa wood, a material more commonly used for model airplanes, is an important element that makes up the floor of the car. Sandwiched between layers of carbon-fiber skins, it reduces weight, sound and vibration while adding structural stiffness.

The three-eighths-inch-thick sheet of wood stretches from behind the seats to around the gas and brake pedals. It is 4 feet long and 1.5 feet wide.

This is not the first time a carmaker has used wood for car floors. Nor is this the same balsa wood used in Cub Scout projects. The Corvette's material comes from the core of balsa trees and is cut across the grain of the wood.

Chevrolet says balsa is the strongest wood for its weight, compared with pine, oak or hickory. Chevy gets the wood from Alcan Baltek Corp. of Northvale N.J.

The composite sandwich of balsa and carbon fiber works better than metals, Tadge Juechter, the car's assistant chief engineer, told Automotive News. "We said, 'Wow - this is great,'" he says. "We were stunned to find out the composite structure was stronger than steel or aluminum."

Juechter says using balsa in the Z06 subtracts about 4.4 pounds from the weight of the car. That's about the weight of four bags of Starbucks espresso roast coffee. That might not seem like much but is significant when aiming for flashy 0-to-60 times.

And though balsa may seem like an unusual material for vehicles, Chevrolet says it got the idea from a group that knows how to make things go fast: NASA. Chevrolet has been using balsa in various Corvette components since the 1997 model year.

GM would not reveal the cost of using balsa, but Juechter says the construction is typical for the Corvette: "We always use the best material."