Hybrid vehicles have been attracting a lot of attention in the last
couple of years, with Toyota, Honda, Ford and Lexus producing hybrids. Now GM is introducing their first real hybrid light duty vehicle and it is powered differently than anything else on the road. It comes from Saturn and is called the Vue Green Line.
The 2007 Saturn Vue Green Line is a "mild" hybrid. It uses a special
generator/motor unit instead of the conventional alternator bolted onto
the engine and it assists the engine's crankshaft through a wider
serpentine drive belt on the front of the engine. GM calls it a BAS
system (Belt/Alternator/Starter). The BAS hybrid system also adds an
electronic controller, 36-volt battery pack under the rear cargo floor
and gauges for the driver. It is a compact system that looks like it
could be easily added to any vehicle with minimal changes to the
existing vehicle. In fact, look for the system to be offered on the 2008 Chevy Malibu too.
Top, the Vue Green Line's BAS unit; middle, the 36-volt battery pack is tucked away under the cargo floor; and information about the hybrid system's workings are relayed to the drive via the Vue Green Line's gauges. Click image to enlarge
Only the "Hybrid" emblems on the front doors and rear liftgate give any
exterior clue to the Vue's inner workings. The driver would notice a
Charge/Assist gauge beside the tachometer, but otherwise the Vue Green
Line looks very much like its non-hybrid counterpart. It even appears to operate much the same.
The 2.4-litre four-cylinder engine still has a conventional 12-volt
starter for initial start-up. Once the engine is warm, much of the
estimated 20% improved fuel economy comes from the hybrid Auto Stop
feature. Pull up to a stop sign or light and the engine smoothly comes
to a complete stop. Electric power steering, auxiliary water pump and an electric pump inside the four-speed automatic transmission keep
everything else operating when the engine stops. Release the brake pedal and the BAS system starts the engine through the drive belt instantly and smoothly.
I did find that when starting out with a cold engine, it took a while
for the engine to warm up before the Auto Stop feature became
operational. The driver can select two different operating modes when
the air conditioning is on. Push the AC button on the dash once, and a
green LED comes on indicating the system will still use Auto Stop even
though AC is requested. Press the button again and an amber light comes
on and the Auto Stop feature is disabled in favour of maximum AC
performance.
2007 Saturn Vue Green Line. Click image to enlarge
Compared to other hybrids, I found the BAS system provides a different
type of assist to the gas engine. Accelerate briskly and the
Charge/Assist gauge needle swings quickly to the end of the Assist range but then quickly returns to indicate minimal assist. Electric motors provide maximum torque at or near stall speeds and this is when the BAS system provides the most power. Driving down the road, the gauge needle shows the system is almost always providing a little assist at highway speed, but back off the throttle or step on the brake pedal and the gauge instantly moves to the charge position. The operation of the hybrid BAS system is not as obvious as some other hybrids but combined with the gas engine does put out 170 horsepower compared to only 144 in the conventional four cylinder Vue. One more hybrid feature is the green "ECO" light on the dash that turns on when the vehicle achieves or exceeds its rated fuel economy.
On the road, the ride feels a little firmer than most compact SUVs, likely due to the vehicle's low rolling resistance tires. Ride height is also lower by 25 mm to reduce aerodynamic drag and improve fuel economy. The electric power steering is better but still feels a little numb to me (again perhaps due to the tires).
2007 Saturn Vue Green Line. Click image to enlarge
The Vue was redesigned in 2006 and retains that styling for 2007. This
compact SUV has fair room for five and the cargo area is practical and
roomy. Most of the controls are arranged nicely and convenient to use,
although I would prefer the four power window switches grouped together
rather than placed around the console shifter. My Vue was equipped with power driver's seat, leather seating, heated front seats and XM satellite radio to keep passengers comfortable and entertained. (Curiously, according to the General Motors of Canadan website, the two option packages included on the test vehicle both include power adjustable and heated front seats: Ed.)
One more advantage of the Vue Hybrid - it can be flat-towed behind an RV, a feature many people with motorhomes may want to take advantage of.
Jim Kerr is a master automotive mechanic and teaches automotive technology. He has been writing automotive articles for fifteen years for newspapers and magazines in Canada and the United States, and is a member of the Automotive Journalist's Association of Canada (AJAC).