Automotive manufacturers are working hard to improve the fuel efficiency of their vehicles without sacrificing internal space, comfort, or performance. Having concluded that the energy density of battery technology is unlikely to increase enough and prices are unlikely to fall far enough in time to enable them to meet upcoming emissions (CO2) legislation, automakers are investing heavily in technology that delivers greater fuel efficiency in conventional vehicles rather than switching the majority of their fleets to electric or hybrid drive. Battery electric and hybrid vehicles will continue to be developed and offered, but the gasoline and diesel internal combustion engine (ICE) will remain the primary source of motive power for the foreseeable future, as described in more detail in Navigant Research’s report, Transportation Forecast: Light Duty Vehicles.
Slimmer & Sleeker
In a recent Investor Day presentation by Fiat Chrysler Automobiles (FCA), the company pointed out that CO2 emissions are highly influenced by weight in the EPA’s city drive cycle. The biggest factor in the highway test cycle is aerodynamic resistance. Tire drag is the other major factor in both cycles, but it’s much harder to reduce while retaining acceptable ride and handling properties. So the manufacturers are focusing most of their efforts into weight reduction and aerodynamic improvements. Most of the changes are incremental, in the hope that many small benefits will combine to make a significant overall improvement.
BMW concluded in the early stages of the development of its electric i3 and i8 vehicles that incremental changes would not give them enough improvement. Rather than simply exchange the conventional powertrain for a battery and electric motor in an existing model, engineers developed an entirely new architecture for the new range of vehicles, which included new materials, such as carbon fiber, and new manufacturing processes. Other volume manufacturers have, so far, taken a more cautious route and focused on smaller improvements to components while maintaining current vehicle architecture.
DeltaWing Technologies is a company best known for developing a radically different racing car that is currently competing in IMSA sports car road races. It is now looking to partner with major automakers to develop vehicles that will meet and exceed the fuel efficiency targets of the future. The DeltaWing concept is a radical change from most current road vehicles. The engine is located at the rear, and the front wheelbase is narrow with thinner tires that reduce rolling resistance without sacrificing road holding. The distinctive shape has improved aerodynamic properties over conventional vehicle shapes, and the overall design uses lightweight materials extensively.
According to the company, its concept vehicle offers a 35% reduction in overall mass and consumes 35% less fuel for equivalent performance in a four-passenger sedan. The current performance targets are 0 to 60 mph in about 6 seconds, 130 mph top speed, and up to 70 mpg when using a small displacement, four-cylinder engine producing between 85 and 110 horsepower. These specifications are clearly attractive to OEMs. It will be interesting to see if any are prepared to commit to such a radical change. A more detailed analysis of the options under consideration is included in our upcoming report, Automotive Fuel Efficiency.
Tags: Advanced Transportation Technologies, Clean Transportation, Smart Transportation Program
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