By: Rex Roy
The Auto Channel
Remember when Saturn offered buyers a different kind car because it was a different kind of car company? While a brilliant advertising campaign, it used to be true. Saturns had their own chassis, polymer body panels, engines, manufacturing plants, dealerships … the works. If you haven't been paying attention (and millions haven't) Saturn is now just another division of General Motors. This may not be a bad thing. The old L-Series were forgettable, Ions were lamentable, and their Relay minivans don't even warrant a pejorative adjective.
Saturn's soon-to-be current line up looks much better. The Aura sedan is terrific. The Sky is an o-so-fine roadster. And the new Outlook crossover is available just as people are awakening to the stupidity of using big SUVs for minivan tasks. The recently announced 2008 Astra completes the picture, adding a dash of European flair to the division that GM neglected like an ugly stepchild for so many years.
But what about the 2007 Saturn Vue? How does it fit in? Actually, it's a holdover from the original Saturn way of doing things. Unlike other vehicles that share its basic architecture (Chevrolet Equinox, Pontiac Torrent, Suzuki XL7), the Vue has rust-proof and dent-resistant body panels and its own engine line up. For years the Vue has been GM's only SUV to offer the corporation's efficient Ecotec 4-cylinder. The optional motor, strangely, was a fine Honda-sourced 3.5-liter V6. For 2007, Saturn added another unique engine, a mild-hybrid. This is the topic de jour.
A different green technology
Since plenty has been written about the gasoline-powered Saturn Vue in standard and high-performance Red Line trim, we'll focus attention on what makes the Vue Green Line different. It's all under the hood. Pop it open and you'll see what looks like a standard 2.4-liter 4-cylinder engine with a really big alternator. A skilled backyard mechanic would also recognize that there is no hydraulic power steering pump, and that the engine control module is super-sized. If this is supposed to be a hybrid, it sure doesn't look like what's under the hood of a Ford Escape or Toyota Highlander Hybrid. The Vue Green Line looks downright conventional.
This is absolutely by design, as GM's goal with the Green Line is to offer a 20-percent increase in fuel economy at a very low cost. The Green Line hits both goals, achieving an estimated 27 mpg city and 32 highway (29 mpg combined). This is a considerable improvement over the less-powerful base Vue that racks up figures of 22 mpg city/27 highway (25 mpg combined). The cost premium for the Green Line is less than $2000 over that of the standard 4-cylinder Vue. To keep things in perspective, the Ford Escape Hybrid, a much more sophisticated full gasoline-electric hybrid, is priced a full $5,500 over its conventionally powered counterpart. In this trade of green for green, the Escape hybrid provides a whopping 50-percent increase in city fuel economy combined with an 18-percent on the highway (36 city/31 highway).
The go behind the green
The star of the Green Line's engineering show is the dual-purpose motor-generator—that big alternator. Hung off the side of the engine in plain view, it not only performs the function of an alternator, but performs like an electric motor, delivering torque back to the gasoline engine when the power is needed most. The gasoline engine produces 170 horsepower and 164 pound-feet of torque, with another 115 lb-ft of torque on call from the electric motor.
This solution is elegant in its simplicity, as it enables the balance of the powertrain to remain much closer to a standard non-hybrid unit, saving on engineering and manufacturing costs. Electric power for the power steering, climate control and other accessories is driven by a modest battery pack that fits unnoticed behind the rear seat under the cargo floor.
Driving the green mile
On the road, the Green Line performs much like any other Vue, only you'll go farther on a tank of gas. The Vue starts conventionally, with no unfamiliar noises or physical sensations. Under acceleration, the 4-speed automatic shifts smoothly. It's only when you lift off the accelerator pedal that you note something different. Most vehicles coast with only a vague sense of slowing — not the Green Line. If you're not on the accelerator, you're slowing down, a result of the Green Line's regenerative braking system that is busy converting kenitec energy into electricity stored for later use. Applying the brakes also takes some getting use to, as they grab quickly and take lots of practice to achieve a smooth chauffer's stop.
Like other hybrids, the gasoline engine shuts down when the Vue is at rest. It is a funny sensation to have the engine just stop, and it took days to fight the urge to restart the engine at each traffic light. The electric motor/generator comes into play most often when accelerating from a rest. As the driver's foot releases the brake pedal, the motor-generator spins the engine's crankshaft up to speed in order to assist the gasoline engine with a smooth launch from a stop. The motor is also capable of providing additional torque when maximum acceleration is called for. Unlike other current hybrids, however, the Green Line does not run any distance on pure electric power; the motor-generator is a hybrid "helper."
Keeping track of all that is happening is a conventional gauge cluster. Unlike the unique instruments found in a Toyota Prius, Camry Hybrid, or the Escape Hybrid (imagine active diagrams charting energy use and flow), the Green Line's instrumentation is basic. Close inspection reveals a charge gauge that indicates when power is being added to or sucked from the onboard battery pack. Once under way, a telltale light illuminates "ECO" (for economy) when you're driving in a frugal manner — beating the EPA's fuel-economy figures. For those who pay attention to the tachometer, it has a position below zero rpm. Interesting, eh? The needle points there when the gasoline engine is not running in situations such as being stopped at a traffic light.
Shorts in the system
The entire system works well, but with two minor hiccups. The Ecotec engine doesn't re-start with buttery smoothness. Every the engine comes to life, it transmits a vibration through the passenger compartment, acting as a reminder that it's again burning fossil fuel. The 2007 Toyota Camry Hybrid starts more smoothly.
The second issue is the steering. The Green Line utilizes electrically-assisted power steering. With the advances in video game technology, it would be an insult to the video games to compare the two in regards to steering feel. For many drivers the Green Line's lack of steering feel will not be a critical flaw. Driving pleasure is not part of this SUV's DNA, as it is with the Sky or Aura.
Other performance benchmarks are completely acceptable for parents hauling kids or environmental activist doing whatever they do when they're not cursing auto manufacturers. Acceleration to 60 mph comes up in a bit over 10 seconds, and there is adequate power to feel comfortable at a 75 mph cruise. Wind noise, especially along the windshield header, infiltrated an otherwise pleasant and comfortable cabin (the Vue received a refreshed, contemporary interior in 2006).
A lame duck
Saturn showed the 2008 Saturn Vue in November at the LA auto show. This model will replace the 2007 Vue sometime this summer with a Green Line version due in the fall of 2007. The newer model should prove to be a better performing vehicle, as it will use GM's new two-mode hybrid system that delivers a 45-percent gain in combined fuel economy verses the non-hybrid Vue model, GM says.
If you feel the need to drive a hybrid SUV, the current Vue Green Line is a solid choice. Keep in mind that a $2000 premium will require about eight years of driving 15,000 miles per year to earn back your savings in saved fuel.
Base Price: $22,370
Engine: 2.4-liter I4 with 170 hp/164 lb-ft, plus 115 lb-ft electric motor
Drivetrain: Four-speed automatic, two-wheel drive
Length x width x height: 181.3" x 71.6 x 65.3"
Curb weight: 3474 lbs
Fuel economy (EPA city/hwy): 27 city/ 32 highway
Safety equipment: Front air bags, anti-lock brakes, traction control, available head curtain side airbags
Major standard equipment: Air conditioning, remote keyless entry, rear-window defroster, steering wheel radio controls, power windows, driver seat height adjustment, AM/FM/CD audio system, cruise control
Warranty: Three years/36,000 miles bumper to bumper, five years/100,000 miles on powertrain components
source: The Auto Channel