Reinventing the Wheel

New hybrid cars and alternative fuels could make our love affair with the car a little less dirty. With gas prices soaring, oil reserves shrinking, and our climate heating up, we all need ways to cut consumption and clean up our act.

Small + Diesel

Every year the Canadian government gives “EnerGuide” Awards to the most fuel-efficient vehicles. In 2005, small diesel cars placed well. This is because a smaller engine uses less fuel than a larger one, and diesel fuel provides up to 25 percent more energy per unit than gasoline.

The Volkswagen New Beetle TDI Diesel won first place in the subcompact class. The Smart Car by Mercedes-Benz placed second in the two-seater class. A larger diesel car, the Volkswagen Jetta TDI Wagon, also placed first in its class.

Diesel Comes Clean

We’ve all driven behind a diesel bus or van that’s spewing smoke and fumes. Diesel releases 20 percent less of the primary greenhouse-gases (CO₂) that cause climate change, but more “particulate” or soot emissions than gasoline. The soot causes smog, which causes respiratory and other diseases, but it’s the high sulphur content of North American diesel that’s at fault. It destroys emission control devices in many diesel vehicles.

This June, the US and Canada will enforce the use of low-sulphur diesel fuel in all road-going diesel vehicles, which will reduce particulate emissions by a whopping 90 percent. Diesel, however, is still made from fossil fuel. The new hybrid technology aims at reducing our dependency on finite resources.

Hybrid Ingenuity

When idling, coasting, or moving at low speeds, a full hybrid car doesn’t use its gasoline engine at all. Electric motors, fueled by a high-powered battery, power the car. At higher speeds the gas engine kicks in. At hardest acceleration the gas engine and electric motors power the car together.

A so-called “mild” hybrid (the Honda Civic, for example) always needs power from the gasoline engine. The “full” hybrid can operate on electricity alone or combine the two modes, which saves more fuel. But the true genius of either hybrid design is that it regenerates energy.

In a gasoline car, the fuel creates a mechanical power to turn the wheels. When braking, the energy of the car moving forward is lost to heat. In a hybrid, this energy is recaptured by electric motors on the wheels, acting as generators, and stored in the battery for later use. This is called “regenerative braking.” A hybrid recharges itself every time you step on the brakes, so stop signs become a source of energy.

According to the Sierra Club, the popular mid-size Prius (a full hybrid) from Toyota produces only 30 to 50 percent of the emissions of gasoline cars. Can even an SUV be redeemed in a hybrid?

Fuel Cell Vehicles

Now imagine a hybrid car with its gas engine removed that has access to an unlimited supply of electricity. This is what manufacturers who are developing fuel cell vehicles (FCVs) are striving to provide.

In a partnership with the government of Canada, the Ford Motor Company is testing five Ford Focus FCVs under real world conditions.

The FCV is a four-door sedan that looks like any other, but in its trunk is a hydrogen tank (crash tested), and in its guts are fuel cells and batteries. The fuel cell device contains a platinum catalyst that combines the lightweight, nontoxic element hydrogen (H) from the tank and oxygen (O) from the air to produce water (H₂O) and electricity.

Clean water is released from the tailpipe: it’s the car’s only emission. The electricity fuels the electric motors/transaxles that turn the wheels and power the car. No gasoline is used at all, and the car also uses regenerative braking to recover energy.

So far, most hydrogen prototypes get their hydrogen supply from natural gas, a finite fuel, or from electrolysis (from hydroelectricity). Fuel cells are also exorbitantly expensive and have
trouble running in cold weather, so there’s more work to be done before FCVs can become the sustainable energy machines we need them to be.

The Road Ahead

With hybrids and more fuel-efficient vehicles around, it’s surprising to learn that carbon emissions are actually increasing.

From 1990 through 2003, CO₂ emissions went up 25 percent in the US because manufacturers put more “light trucks” (gas pickups and SUVs) on the market. These vehicles have looser emission standards than cars and, in 2003, emitted 38 percent more CO₂ per mile/km than new cars.

To ensure a clean energy future, it looks like consumers and public policymakers will have to encourage automakers to keep reinventing the wheel.

Smart Car, Mercedes-Benz

This two-seater with a turbo-charged diesel engine zips along up to 135 kph (80 mph).

Turn the key and the digital display tells you when the car is ready to go–about two seconds
in warm weather. The six-speed semi-automatic transmission lets you manually up-shift the
gears or have the car do it for you. The feeling of drag when the gears shift in automatic makes manual preferable.

The road noise is comparable to other small cars, but for the most part the Smart belies its tiny stature with stability at high speeds, ample leg room, and luxury seats set high so you can meet the eyes of other drivers. Only when you step out do you realize you’ve been driving an uber mini.

Fill up? $17. Parking? No problem. Two Smarts fit into a regular parking space. Some Canadian cities are even creating special parking slots for them.

Highlander Hybrid 2006, Toyota

This luxury mid-size SUV is wrapped around a golden nugget of common sense.

As you slip quietly onto the street, powered by electricity alone, a schematic on the dashboard shows you where the power is coming from and going to. When you brake or coast, it’s a thrill to see the energy arrow charging back to the battery. The high-powered battery is made of modules, so if problems arise it can be replaced piece by piece to save on maintenance costs.

With its V6 engine, the Highlander can tow up to 1,587 kg (3,500 lb) and easily accommodate a family, but what’s fuel consumption like? An impressive 7.5L/100km (38 mpg) in the city and 8.1L/100km (35 mpg) on highway. Better yet, C02 emissions are 3,730 kg/year, about half as much as conventional SUVs produce.

This SUV hybrid might just make its gas-guzzling cousin obsolete.

PDF Chart of Fuel-Efficient Diesel