DOE: automotive use of lightweight materials has increased over last 20 years even as weight increases
As automakers strive to improve fuel economy, they have turned increasingly to lightweight materials to reduce overall vehicle weight—even though the average weight of materials in North American light vehicles has increased from 3,694 lbs (1,675.57 kg) in 1995 to 3,994 lbs (1,811.65 kg) in 2014, according to figures from the US Department of Energy (DOE).
Use of regular steel has declined by more than 250 lbs (113.4 kg) per vehicle from 1995 to 2014 from 1,630 lbs (739.36 kg) to 1,379 lbs (625.5 kg). At the same time, the use of high- and medium-strength steels has doubled, increasing by 325 lbs (147.42 kg) per vehicle—from 324 lbs to 649 lbs (294.38 kg).
|Source: DOE. Click to enlarge.|
The increased use of high- and medium-strength steel is significant because it allows manufacturers to improve the structural integrity of vehicles while keeping the overall vehicle weight to a minimum.
The use of iron castings per vehicle has dropped 42% from an average 466 lbs (211.37 kg) in 1995 to 271 lbs (122.92 kg) in 2014.
Aluminum use in the average light duty vehicle has increased 72% from 231 (104.78 kg) lbs in 1995 to 398 lbs (180.53 kg) in 2014.
The use of plastics and composites has also increased by almost 40% (from 240 lbs/108.86 kg to 329 lbs/149.23) and lightweight magnesium castings have seen greater use (from 4 lbs/1.81 kg to 11 lbs/4.99 kg) in dashboards and other interior applications such as seat components, replacing the heavier steel components that were previously used.
All figures are from the Oak Ridge National Laboratory Vehicle Technologies Market Report.