With U.S. mileage standards set to rise to 54.5 miles per gallon (4.31 liters per 100 km) by 2025, Carmakers are working flat out to make their vehicles burn as little fuel as possible. One approach is to develop new drivetrains based on hybrid or all-electric technology, but regardless of the platform, weight reduction remains very much a part of the equation. Toyota is pointing to its 2013 Avalon as an example of its progress on this front, having designed the mid-size sedan with 110 pounds (50 kg) less weight than the 2012 model.
Lightening a car seems like an easy thing to do, but in practice it’s a tricky balancing act of requirements and tradeoffs. Do you make the car lighter by using less steel? But if you do that, how do you protect the passengers in crash at the standard required by law? You could put in a lighter engine, but that may mean poorer performance. Or you could use composites, but that puts up the price. On the other hand, reducing weight in one area allows for savings in others. A lighter chassis, for example, means that smaller tires can be fitted for even more savings.
Based on the Lexus ES, the Avalon is Toyota’s flagship sedan. It's built in the United States and Australia for the for the North American and Middle Eastern markets.
Toyota took a broad approach to the task of making the Avalon both lighter and more rigid so that the weight reduction would be rewarded with better handling.
“We established two main mass targets early in development: lowest mass among competitors (mass vs. vehicle size) and reduction of one inertia weight class rank," says Dave Katarzynski, Program Manager of Avalon Vehicle Development. "As part of each design engineering group's agreement, mass targets were set for each group. The groups then managed their part by part mass to keep their target and help control the overall goal. Hundreds of mass reduction ideas were tracked throughout development and periodic reviews checked status.”
One form of weight reduction was replacing the polypropylene resin used in the bumpers with a more fluid high-performance version. Another was using high-strength steel in the pillars and rocker panels to lighten them while maintaining safety standards.
These and similar reductions give the new Avalon Hybrid sedan a weight of at 3,461 lbs (1570 kg), compared to 3,571 lbs (1620 kg) for the 2012 model. Toyota says the car will make 40 mpg and will be the lightest vehicle in the premium mid-size segment when it hits showrooms later in the year.