2009 Best New Green Technology contenders

MICHAEL BANOVSKY FOR THE TORONTO STAR

Although it looks unassuming from the outside, this Subaru Legacy is a Partial Zero Emissions Vehicle.

Gerry Malloy

SPECIAL TO THE STAR

Recognizing the importance of environmental issues in today's automotive market, AJAC's Canadian Car of the Year group added a new category to this year's awards – Best New Green Technology.

While the winner won't be announced until the Montreal Auto Show in January, presentations of the nominated technologies were made to the voting panel at TestFest last week. This panel consists of 10 selected AJAC members with specific technical expertise, including Wheels contributors Jim Kenzie and myself.

The four nominees:

General Motors two-mode hybrid system

GM's two-mode hybrid system, which has evolved from a concept initially developed for hybrid city buses, is currently offered in the Cadillac Escalade, Chevrolet Tahoe and GMC Yukon SUVs, and will soon be available in the company's full-size pickups and the Saturn Vue compact CUV.

Unlike other hybrids, the core of the system is an integrated combination of two electric motors and a conventional automatic transmission gearset housed within a conventional transmission case. The two motors work in conjunction with each other and the planetary gearsets to act as, in effect, a four-step automatic transmission with variable ratios in each step and multiple power inputs.

Vehicles with the two-mode hybrid system always start off in electric mode and can operate for short periods only in electric mode. But its greater benefit is in offsetting some of the load normally carried by the gasoline engine, thus reducing its fuel consumption – by up to 33 per cent, depending on the application. Because of its unique configuration, the two-mode hybrid system does not limit payload or trailer-towing capability, which is why it is particularly well suited for trucks.

Mercedes-Benz BlueTEC II diesel

Last year, Mercedes-Benz introduced its BlueTEC clean-diesel technology in Canada in the E320 sedan. BlueTEC II, which is available in the 2009 R-Class, ML and GL, takes that technology a step further, satisfying current and forthcoming emissions regulations throughout North America, including California.

It varies from the previous version by the addition of a "wet" after-treatment system in the exhaust to treat nitrogen oxide (NOx) emissions – one of the major ingredients in smog – which are inherent products of lean combustion in diesel engines. The system is called "wet" because it involves the injection of a urea-based liquid called AdBlue into the exhaust system ahead of its selective catalytic reduction (SCR) catalyst. When the AdBlue is injected into the exhaust it is converted to ammonia, which is then stored in the SCR cat. When NOx enters that converter, it reacts with the ammonia to form water and nitrogen.

While the system is somewhat complex, it means today's modern diesels can meet the same exhaust emissions regulations as gasoline engines, thus enabling access to the other advantages of diesel, including reduced fuel consumption and high torque output.

Subaru PZEV

California, which has the world's toughest vehicle emissions standards, has several unique levels of vehicle certification, one of which is PZEV – partial zero emissions vehicle.

The cleanest of all internal combustion engine vehicles, PZEV's tailpipe emissions are 90 per cent cleaner than those of vehicles meeting the already clean Tier II, Bin 5 standards required by Canadian and U.S. regulators.

The PZEV regulations aim to eliminate evaporative emissions, as well as exhaust emissions. Evaporative emissions are those resulting, for example, from gasoline evaporating into the air through the intake air filter or from the gas tank. Several PZEV models are available in California but few have made it to Canada, until now. Subaru is offering base-level PZEV models in both its 2009 Legacy and Outback lines.

They achieve their PZEV status through a combination of precise engine calibration and exhaust after-treatment, and the addition of specific components to prevent or capture evaporative emissions. The latter include gasoline filler necks compatible with the sleeve-like gasoline nozzles used in California, but not currently in use here. Subaru is offering its PZEV models at no additional cost.

Volkswagen Jetta TDI

Volkswagen has reintroduced diesel engines to Canada in the form of the Jetta TDI (turbocharged direct injection) sedan and wagon.

A combination of technologies, including common-rail direct injection, pressure-regulated combustion, advanced EGR (exhaust gas recirculation) and variable-vane turbocharging, enables the vehicles to meet the same Tier II, Bin 5 exhaust emissions regulations as gasoline-powered vehicles.

While they also employ sophisticated exhaust after-treatment systems, including a particulate trap, because of the vehicles' relatively low mass and small engine size, they do not require the use of urea injection in the exhaust, as is the case for most other diesels currently offered in Canada. While they offer similar fuel economy advantages and corresponding carbon dioxide reductions, these new TDI diesels are up to 90 per cent cleaner than Volkswagen's earlier diesels.

All of these green technologies are winners in their own right, making it very difficult to choose one as more significant than another. Forced to do so, I chose Subaru's PZEV technology on the basis that it could be implemented by most manufacturers at relatively little cost to customers. But to be fully effective, it would require that fuel suppliers get on board by providing gasoline pumps with vapour collection nozzles. And that step will probably require some regulatory intervention.

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