Handling and Performance

The principal reason for using aluminum in automobile construction is to reduce weight in order to reduce fuel consumption and exhaust emissions. However, there are many other advantages in using aluminum, including improved acceleration and braking, and better noise, vibration, and harshness (NVH).

Acceleration—A weight reduction from 3,400 to 2,600 lbs. would reduce the 0 to 60 mph acceleration time for a mid-sized sedan from 10 to 8.2 seconds—an 18 percent improvement..

Handling—Reduced vehicle weight leads to improved stability and turning response. Weight reductions decrease the slip angle between the tire and the road for any given turning situation (i.e., lateral acceleration), allowing a vehicle to respond more directly and safely to steering inputs. This is shown on the chart below relating the yaw phase lag to the lateral G-force phase of the lag.

Noise, Vibration and Harshness (NVH)—A car's torsional rigidity influences both the response to steering input and the way the road-generated noise and vibrations are amplified by the vehicle structure and transmitted to the occupants. The challenge is to obtain a high frequency for the first mode of torsional vibration without building a heavier car.

The next chart shows how aluminum can result in vehicle structures that are more rigid than steel yet significantly lighter. The aluminum examples include both spaceframe and unibody construction methods.