Lexus: The hybrid debate blog

Hybrid engines can play a major role in increasing vehicle efficiency, but their promise won’t be fulfilled unless the components packaged around them achieve proportionate gains. Right now there are some conventional cars that have lower emissions than the average hybrid. In the future, as public awareness of sustainable living grows, attention will naturally be drawn to other car components that could contribute towards vehicles becoming more efficient and less environmentally damaging.

As Amory Lovins of the Rocky Mountain Institute [1] points out [2], if the clean technologies already available today in some cars were fitted into all cars, total fuel consumption would be cut by a quarter.

Lovins argues that radically reducing weight is the key to improving a car’s fuel efficiency, since 75% of the energy required to move one is related to its weight. Building car bodies using new materials such as ultra-light steel can double their efficiency without compromising price or safety. And advanced polymer composites such as thermoplastics can halve weight and fuel-use while increasing safety (not to mention absorbing 12 times as much crash energy per pound as steel), with any additional cost being recouped in fuel savings over the first two years.

According to Lovins’ calculations, further efficiencies could be achieved by ultra-light hybrid cars using alternative fuels, with a 15% gasoline and 85% ethanol mix cutting oil requirements by a further 75%, to just 7% of current usage levels.

Minimising aerodynamic drag is also important, and while manufacturers have been moving towards sleeker designs, more explicit recognition of this would help, especially if combined with in-car devices designed to encourage drivers to optimise their vehicle’s aerodynamic performance – for example, dashboard alerts to close windows when exceeding 45mph or to remove unloaded roofracks.

Providing multiple options for car-buyers in these areas could help smooth the transition to widespread use of cars that are all-round efficient. Buyers could weigh up any additional up-front costs of efficiency-improving features against reduced running costs; tax incentives, and other perks such as free parking or exemption from the London Congestion Charge; and point-of-sale penalties for less efficient cars (also known as the “showroom tax,” as mooted recently by the Tories).