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the green highway

Hybrids are great in the city, electric cars will be terrific for short-range commuters, hydrogen fuel cell cars could break us free of petroleum if we live long enough, but the greatest new green technology on the market today is GDI. That's Gasoline Direct Injection. It's been available mostly in the high-end German stuff for a few years now but starting today it's standard equipment in a little South Korean econo-box.

That's going to make Hyundai mad because its Accent is so much more than an econo-box these days. The 2012 is loaded with features. But it's the standard equipment engine in the Accent, the 1.6-litre four-banger, that has me excited.

Your plain old gasoline engine sucks a mixture of gasoline and air into a cylinder, compresses it with a piston and lights it with a spark. The explosion sends the piston downwards eventually turning the wheels. Fuel-injected engines pre-mix the gasoline and air in the intake manifold before it goes into the cylinder. In Direct Injection the air and gasoline are not pre-mixed and each comes in a different way: air comes in through the intake manifold, while the highly pressurized gasoline is injected directly into the cylinder.

With GDI you have a sophisticated Engine Management System (EMS, a computer) measuring all kinds of temperatures, loads and driver inputs so you get extremely accurate fuel metering and injection timing. Plus the high-pressure injector fires the fuel just where it will do the most good, and maybe a few times on each cycle. The result is much more complete combustion, which means you're squeezing more power and less pollution out of each drop of gas.

All this sounds great and it is, but it's also expensive (see high-end German stuff above). What I like about Hyundai's approach is that it is putting GDI in its entry-level car (see, I'm not calling it an econo-box any more). Yes, you can get GDI from other volume manufacturers but it's generally an expensive option and nobody else offers it at any price on a sub-compact.

Ford has a different version of GDI and it calls it EcoBoost, and it is an expensive option. EcoBoost adds turbo-charging to GDI and gets even more horsepower out of a little engine. The Accent's 1.6-litre cranks out an amazing 138 horsepower. Ford's 1.6-litre EcoBoost does an even more amazing 150 horsepower with the turbo added on.

Customers like power and GDI delivers it, especially when combined with goodies like Continuously Variable Valve Timing and a Variable Induction System. Fuel economy goes way up and emissions come way down. Making it standard, not optional, on a $15,000 sub-compact is what tickles me.

Gasoline engines are going to be with us a long time and GDI is one of the main reasons why. It's also the reason why E85 ethanol might be even more attractive as a petroleum replacement in the near future. Manufacturers are fiddling with the EMS to get the very most out of the renewable fuel. It's assumed today that a tank of E85 gives you up to 20 per cent less power to the wheels than 100 per cent gasoline. Properly engineered GDI might go a long way to reducing that gap. So bring it on.

If they can put an excellent GDI in the once-lowly Accent then I think it should be in everything else on the road that burns gas too.

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