Composite materials are at the high-end of the spectrum of ways we can reduce weight. However, light alloys, aluminum and magnesium are also up there. In the unique case of the LFA, where we wanted low weight to optimize performance, the overall structure makes complete use of all these materials. If you put a magnetometer on an LFA, you’re not going to find a lot of steel in the car. Two-thirds of the vehicle’s basic structure by weight is carbon fiber composite (CFRP) and the remaining third is aluminum. You’ll also find extensive use of aluminum and some magnesium in the suspension and in the engine as well. Performance vehicles have their own needs, but whatever we learn with this car we need to spread more broadly across our mainstream models.
For a manufacturer, what is the purpose of a hybrid vehicle?
When you say the word hybrid, the average American buyer thinks high fuel economy. But that’s not why Toyota makes a hybrid, that’s secondary. Our motivation is a little different from our customers’. The reason we make hybrids is because they have far lower emissions than conventional vehicle and they get substantially better fuel economy. However, the primary driver for us is ultra-low emissions. That pressure is evident in every other part of the vehicle, not just under the hood. We are always looking at ways to improve the vehicle’s performance and reduce its weight to reduce emissions and increase fuel economy.
What role do you see composites playing in the future?
We’re already using composites at the component level in our advanced technology vehicles. We’ve built compressed natural gas vehicles (where the compressed natural gas is stored in a high-pressure tank.) In the past we’ve made those tanks of aluminum wrapped with fiberglass but now we’re developing other high-pressure tanks, possibly out of fiber reinforced metal envelopes, which will be useful in extremely high pressures such as future hydrogen vehicles.
We believe that advance lightweight materials have to go hand in hand with future advanced technology vehicles. Within composites we believe that CFRP will play a role in other advanced technology, advanced powertrain vehicles. Unfortunately, many of these advanced technologies and advanced powertrains carry additional weight penalties. For example, electric motors are heavy; there is no getting around that. In other cases it’s simply because within many of the advanced technologies the power source doesn’t have quite the same energy density as liquid gasoline. To compensate you have to improve the performance of the vehicle in other ways, and light-weighting is one way to do that.