While Toyota's fuel efficiency fame rests on the Toyota Hybrid Synergy drive train powering the Toyota Prius and Toyota's other hybrid cars, the company is looking into weight reduction to also increase fuel efficiency. The 2013 Toyota Avalon is a case-in-point.
The 2013 Toyota Avalon is lighter, yet more rigid, than the 2012 Avalon and will be the lightest vehicle in the premium mid-size segment. The 2013 Avalon has shed 110 lbs over the 2012 Avalon tipping the scales at 3,461 lbs. compared to 3,571 for the 2012 model.
“Our target was to dramatically improve all aspects of dynamic performance,” Avalon Chief Engineer Randy Stephens explained, “Especially in the areas of fuel efficiency, handling and performance.”
The weight reduction plan came head-to-head with another goal, the weight penalty imposed by equipment necessitated by increased regulations, improved performance targets and added customer features. Toyota's engineers collaborated on potential weight-loss areas, stayed focused on an overall weight reduction goal, and achieved significant mass reduction in several key areas like body structure, seat structure and wheel design.
Dave Katarzynski, Program Manager of Avalon Vehicle Development offered this insight, “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. 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.”
While weight reduction acts to reduce fuel consumption, increasing fuel efficiency, the team had additional goals. Namely to improve vehicle dynamics and the driving experience. “Less mass makes Avalon more responsive and engaging near handling limits,” Katarzynski explained. “Also, with less mass, less tire width is needed to reach competitive grip levels. The smaller width helps minimize drag losses to help enhance fuel economy, too.”
Rob McConnell, Principal Engineer, Body Shell and Exterior Plastics, said, “Through the installation of a higher class of high performance polypropylene resin (more fluid), we were able to decrease the general thickness of the front and rear bumpers, resulting in a decrease in mass, aiding in achieving improved fuel economy. Also, by adopting a higher content of high-strength steel in the pillars and rocker panels, we were able to conserve mass while maintaining crash performance targets.”
Significant weight reduction was also achieved for the 2012 Toyota Camry, 3,680 lbs. for 2011 Camry Hybrid vs. 3,417 lbs. for 2012 model. The new 2013 Avalon Hybrid weighs 87 lbs. less than the 2011 Camry Hybrid (3,593 lbs. for 2013 Avalon compared to 3,680 lbs. for 2011 Camry), while offering a combined 40 mpg EPA-rating compared to the EPA rated 33 mpg combined fuel economy of the 2011 Camry Hybrid.
Tin Bui, a Toyota engineer in charge of Avalon fuel economy and road load development said, “To improve the vehicle's fuel economy we focused on reducing the vehicle's resistance which lowers the engine's effort and fuel consumption. One resistance area we worked on is reducing the vehicle's weight. With reduced vehicle weight, there is less resistance to accelerate the vehicle. Lower vehicle weight also reduces the vehicle's tire rolling resistance allowing it to roll more freely.”