The latest Corporate Average Fuel Economy standard requires automotive OEMs to meet an average fleet gas mileage of 54.5 mpg by 2025. This will require radical improvements in engine technology as well as drastically lighter vehicles.
Using aluminum instead of steel can decrease the weight of a car body up to 50 percent. For example, the latest Audi A8, with its aluminum chassis, is a whopping 527 pounds lighter than the original 1994 model, which had a steel chassis.
Initially, joining aluminum represented quite a challenge. Now, however, automakers have numerous options, including riveting, MIG welding and laser welding.