There are many factors that affect fuel efficiency. Click image to enlarge
By Jim Kerr; photo by Chris Chase
Although the price of gasoline is lower now than the record highs of last summer, most drivers are still looking ahead to the future and predicting higher fuel costs. That is influencing what we buy, but what will the future hold in the way of new technology to lower our driving costs?
Some look to the electric car, others to hydrogen, but in reality, we are likely to see several technologies converge to produce the fuel efficient cars of tomorrow. Some of these technologies were recently showcased at the North American International Auto Show in Detroit.
Hybrids continue to take the spotlight in the race for economy and the Toyota Prius has to be the most recognizable hybrid on our roads. A new 2010 Prius will be in the showrooms this summer, and although larger and 22 per cent more powerful, this car will also set new fuel economy standards. Estimated to achieve 3.8 L/100 km (74 mpg Imperial) combined city/highway fuel economy, this car is seven per cent better at conserving fuel than the previous Prius model. Improvements in aerodynamic drag ( .25Cd), lower vehicle weight through the use of aluminum panels for hood and rear hatch and lighter hybrid components all help with the fuel economy. Even small items such as an electric water pump and solar panels on the roof that power a vent fan to keep the interior cool on hot days (which reduces the need to run air conditioning) reduce loads on the engine and improve economy; the icon for hybrid vehicles is still setting the benchmark.
Tire rolling resistance lowers fuel economy. There are two areas of rolling resistance that manufacturers look at. The first is the resistance of the tire to roll through the air: smooth hubcaps or wheels, close fitting wheel openings and minimizing the tire offset help reduce the aerodynamic drag. There are practical limitations to vehicle design that limit the amount of improvement we can get, such as having room to fit tire chains or to be able to grip tires in the wheel opening, or the requirement for steering and suspension travel with varying loads and road surfaces, but look at many new vehicles and you can see that tire openings do fit closer to the tires, and that the tires are flush with the outside body panels of the vehicle.
Rolling resistance of the tire on the ground also reduces fuel economy. It is easy to make a low rolling resistance tire by making a narrow, non-flexible tire with hard rubber, but that wouldn’t be a safe tire as it couldn’t grip the road surface. Michelin showcased their line-up of low rolling resistance tires, the Energy Saver all-season passenger tire. Fuel savings are combined with superior grip and a long tread life. You can already find low resistance tires on the market – all 2009 Ford Escape models use them, for example, and Michelin is making it easy to recognize their line of low rolling resistance tires by looking for the “Green X” symbol on the sidewall. Low rolling resistance tires combined with the proper tire inflation will help maximize fuel economy.
Electric vehicles continue to spark the imagination, with the 2010 Chevy Volt set to be introduced. Capable of delivering up to 40 mpg (US) on gasoline and emission-free driving on electric power, the Volt will use state of the art Lithium-ion battery packs manufactured at a new plant in Michigan. GM wasn’t the only company to promote electric vehicles at the Auto show: Mercedez-Benz showed off three versions of the BlueZERO concept vehicle. One version of this compact car is a plug-in electric car with a range of around 1250 miles (2000 km) on a single charge. Another variation – the BlueZERO E-Cell Plus – adds a small three-cylinder gas engine that acts like a generator (similar in concept to the Chevy Volt). The third variant, the BlueZERO F-Cell, uses a fuel cell that converts hydrogen to electricity, providing a 350 mile (560 km) range on a tank of hydrogen.
Keeping up with the Jones, Chrysler also showed off their extended-range electric hybrid Jeep Patriot. With 150 kw (think 200 horsepower) the Patriot will go from 0 to 60 in eight seconds and drive on a charge for 64 kilometres. After that, the gasoline engine will cut in to charge the battery for up to a 640 km range. It can also be recharged by plugging it in to a standard 110-volt outlet.
There are many technologies that will be used to keep our cars going down the road economically in the future. Rather than one predominant one, as we have been used to in the past with gasoline engines, there will be many combinations of technologies. The auto shows move these concepts from the labs into the public eye, but you can be sure there are still many more ideas behind the scenes that will improve economy in our future.