Photo Gallery: 2007 Saturn Aura Green Line

North Vancouver, British Columbia – The Saturn Aura Green Line joins a growing list of hybrid mid-size family sedans that now includes the Toyota Camry Hybrid, Toyota Prius, Nissan Altima Hybrid, and soon, the Chevrolet Malibu Hybrid. With a 2007 MSRP of $27,290, the Aura Green Line is four or five thousand dollars cheaper than its Japanese competitors.

Like other gasoline-electric hybrid vehicles, the Aura Green Line uses a powerful battery and an electric motor/generator to assist a four-cylinder motor, shuts down fuel-flow when decelerating, and shuts off the engine automatically at traffic lights, thereby saving fuel and reducing exhaust emissions.

However, there are some distinct differences between General Motors’ “mild” hybrid system and Toyota’s “full” hybrid system (also used in the Altima) which have implications for the Aura Green Line’s comparative fuel economy, performance, and drivability.

2007 Saturn Aura Green Line Hybrid. Click image to enlarge

First, let’s take a look at Aura Green Line’s hybrid technology: first introduced in the Saturn Vue Green Line this year, GM’s BAS (Belt/Alternator/Starter) hybrid system comprises an electric starter/generator motor, electronic controller, and 36-volt nickel metal-hydride battery pack in the trunk. (See Jim Kerr’s Auto Tech column for full details.) A 2.4-litre DOHC 16-valve VVT-i four-cylinder engine and four-speed automatic transmission make up the conventional part of the powertrain. Combined, the two systems produce 164 horsepower at 6400 rpm and 159 lb.-ft. of torque at 5000 rpm.

Interestingly, the Aura’s non-hybrid 2.4-litre four-cylinder powertrain, newly available in the 2008 Aura XE, produces about the same amount of horsepower and torque as the hybrid powertrain. This is unlike Toyota’s full hybrid system which has a much more powerful battery that actually increases combined horsepower and torque. Still, the goal of GM’s hybrid system is to reduce fuel consumption, not increase performance.

2007 Saturn Aura Green Line Hybrid. Click image to enlarge

Official Energuide fuel consumption figures for the 2007 Aura Green Line ($27,290) are 8.5 L/100 km city/6.2 L/100 km hwy, with an average of 7.5 L/100 km. That compares to the new 2008 Aura XE ($24,240) equipped only with the 2.4-litre four cylinder engine and four-speed automatic transmission at 9.6 L/100 km city and 6.5 L/100 km hwy, averaging 8.2 L/100 km. As you can see, the Aura Green Line’s average fuel consumption improves by about 0.7 L/100 km, or approximately 10 percent. It runs on Regular grade gasoline.

However, because the Aura Green Line doesn’t have the capacity to run on electric power alone at slow city speeds, and because it has a four-speed automatic transmission instead of a continuously variable transmission, it’s not as economical as the Camry or Altima Hybrids, which are officially rated below 6.0 L/100 km, but average about 7.2 L/100 km in real-world driving – that’s still much better than the Aura Green Line’s 7.5 L/100 km official rating and actual 10.5 L/100 km I averaged during my week of city and highway driving. Later in 2008, GM plans to introduce an improved “two-mode” hybrid system that will add low-speed electric power to improve fuel economy.

2007 Saturn Aura Green Line Hybrid. Click image to enlarge

With only 164 horsepower and a standard four-speed automatic transmission, the Aura Green Line isn’t exactly a powerhouse: according to Edmunds.com, the Aura Green Line takes about 11 seconds to go from 0 to 60 mph – that’s about two or three seconds slower than a Camry Hybrid or Altima Hybrid.

I found the Aura Green Line perky from a standing start and sufficiently powerful around town, but highway passing was laboured – and this would be worse with four passengers on board. The engine emits a distant buzzy sound when pressed, but is normally very quiet while motoring around town or cruising on the freeway. Engine speed at 100 km/h is just 2000 r.p.m.

While the regular Aura has a towing capacity of 454 kg (1000 lb), General Motors specifically states that the “Green Line is not recommended for towing”.

On the positive side, the shift feel of the Aura’s conventional four-speed automatic transmission is more familiar than the spinny CVTs of the Camry and Altima Hybrids, which improves the driving experience, at least for me. The four-speed automatic transmission shifts very smoothly and responds to kick-down quickly. The transmission selector includes an unusual “I” gear – as in PRNDIL – which stands for “Intermediate”. Selecting “I” operates 2nd and 3rd gears only – I guess this is for those times when you don’t want to go too slow and you don’t want to go too fast.

2007 Saturn Aura Green Line Hybrid. Click image to enlarge

When stopped at a traffic light, the Aura Green Line’s engine shuts off automatically (if the engine is warmed up and the battery is fully charged) and a green ECO light illuminates in the right-hand gauge. As soon as you release your foot from the brake pedal, the engine turns on automatically without lurching, and you can accelerate away easily – it’s mostly seamless. As well, while coasting downhill, fuel is shut off to the engine, and the ECO light comes on to let you know. When braking and coasting, the regenerative brakes recharge the battery. A “charge/assist” gauge lets you know when the battery is helping the gasoline engine accelerate, and when the battery is being recharged.

The Aura Green Line has a very comfortable ride, and absorbs road imperfections quite well. It’s a bit soft in the corners though, and though it has a fully independent suspension, it doesn’t pretend to be a performance sedan. The Aura Green Line’s electronic power steering requires little effort but doesn’t communicate very much feel to the driver.

Standard Uniroyal Tiger Paw P215/60R-16-inch low-rolling resistance all-season radials on my test car were grippy in the dry and quiet at speed, but seemed a bit skittish in the wet. The standard four-wheel disc brakes with ABS offered firm pedal feel and short stopping distances. Both traction control and electronic stability control are standard on the Aura Green Line.

2007 Saturn Aura Green Line Hybrid. Click image to enlarge

The Aura’s turning circle of 12.3 metres (40.4 feet) is a bit wide for a mid-sized car, and I noticed a tendency for the car to wander slightly at high speeds, necessitating slight steering corrections.

All in all, the Aura Green Line is a very comfortable, easy to drive sedan that’s occasionally feels underpowered. Visibility is good to the front and sides, but the rear view is obstructed by a very high trunk lid which makes backing into a parking space a bit of guessing game.

Though the Aura Green Line’s fuel economy is better than the regular four-cylinder Aura, it’s not as good as its competitors, nor is its straight-line acceleration.

My test car had an attractive two-tone instrument panel with faux silver trim and tasteful chrome finishing. Fit and finish is quite good and the layout of the controls is also easy to see and use, with the exception of the (optional) radio/cruise/info steering wheel buttons which seem a bit fiddly.

The three round gauges have large backlit white and orange numerals for easy reference and a digital display which includes information such as average fuel consumption, instant fuel consumption, range, outside temperature and trip odometer. The far right gauge includes a “Charge/Assist” gauge that shows when the electric motor is assisting the gasoline engine and when it, and the regenerative brakes, are charging the battery.

Standard features in the Aura Green Line include front, side and curtain airbags, automatic climate control that includes an Economy A/C mode for saving gas; AM/FM/CD/MP3 stereo with auxiliary jack, six speakers, and OnStar; power windows and power mirrors; automatic headlamps; speed-sensitive variable intermittent wipers, tilt and telescopic steering wheel, cruise control, and 60/40 split folding rear seatbacks.

2007 Saturn Aura Green Line Hybrid. Click image to enlarge

Storage cubbies abound: there’s a small one in the lower centre console with a 12-volt power outlet for phones and players; behind the shift lever is a sliding cover which covers two cupholders, a coinholder, and storage slot. Between the front seats is a deep bi-level storage bin with a 12-volt power outlet inside. There are also door pockets, a flip-down coin tray near door, and map pockets in back of the front seats, and two flip-down cupholders at the rear. But there’s no centre rear folding armrest.

While many hybrid sedans don’t have folding rear seatbacks because of the large battery positioned behind the rear seat, the Aura Green Line does have 60/40 folding seatbacks. GM’s NiMh battery is smaller than in other hybrids and allows a wide but narrow opening when the seats are folded down. The only other hybrid sedan with folding seatbacks is the Camry Hybrid, but its opening is even smaller.

2007 Saturn Aura Green Line Hybrid. Click image to enlarge

One area where the Aura Green Line hybrid compares well with other hybrids is in trunk space. It offers 371 litres (13.1 cu. ft.). Compare that to the Camry Hybrid with 300 litres (10.6 cu. ft.) and the Altima Hybrid with 257 litres (9.1 cu. ft.).