Green lite

IT would be easy -- effortless, even-- to accuse GM of bad faith in the Saturn Vue Green Line, a maximally minimal venture in hybrid powertrain technology that would seem less about fuel economy and more about securing coveted hybrid badges on the doors (and the current $650 tax credit for buyers). Unlike "strong" hybrids from Toyota, Honda, Ford and most recently Nissan, the Green Line project doesn't deploy a gas-sipping Atkinson cycle engine; a continuously variable transmission with exotic power-routing gear sets; an electric air conditioning unit that doesn't depend on the engine running; a powerful electric traction motor; or a large and potent advanced-chemistry battery.

It uses, instead, a big honking belt-driven starter motor that -- with a flip of polarity when the vehicle is coasting and braking -- acts as a generator, feeding electrons to a relatively dinky 10kW battery under the cargo floor. Otherwise, the Green Line powertrain is as conventional as Victorian sex. The internal-combustion smudge-pot is a 2.4-liter four-cylinder engine (a bump from the standard Vue's 2.2 liters of displacement); the gearbox is a straight-no-chaser four-speed transmission (slightly tweaked to account for the hybrid's transient electrical boost under hard acceleration). Unlike other hybrid SUVs, the Green Line is available only with front-wheel drive.

As much as I hate to diss any hybrid, this seems a pretty desultory effort. GM says its mild-hybrid system is cheaper and simpler than other hybrids. Well, we'll see about cheaper, but it is simpler, in the same way "Alfie" played on a comb is simpler than the "1812 Overture."

Saturn is pleased to report the Vue GL's 32 miles per gallon on the highway is the best fuel economy of any hybrid SUV. However, this is a bit of squirmy accounting. When you look at combined city/highway fuel economy, the Vue GL (29 mpg combined) actually gets five miles per gallon less than the Ford Escape FWD (34 mpg). The Vue's combined mileage is comparable to that of the heavier and faster Toyota Highlander Hybrid and the Lexus RX400h. The disadvantage is largely due to the fact that, unlike other hybrids, the Green Line cannot move solely on electric power and so doesn't enjoy as much hybrid benefit around town.