The Saturn Aura was chosen North American Car of the Year for 2007, and with good reason. (Full disclosure: I voted for it.)

It is a gorgeous car with lots of room, a fine interior, good performance, and excellent ride and handling.

The Aura Hybrid promises all this, and better fuel economy too.

Like all hybrids, the Aura combines electric and gasoline power. In this case, it is General Motors' Belt-Alternator-Starter (BAS)
system, which, in effect, connects a big electric motor to the gasoline engine via a belt.

The "mild" terminology means the electric motor does not drive the car by itself as a full hybrid does, although in this case when
an extra burst of energy is needed for a quick start or a passing manoeuvre, additional torque can be applied to the crankshaft
via the belt.

Mainly though, the electric motor powers all accessories, and enables both brake energy regeneration and the idle-stop function.

Come to rest, leave your foot on the brake, and the gasoline engine shuts itself off. When you release the brake, the engine instantly
clicks back to life.

Idle shut-off is one reason why hybrids do so well in city fuel consumption tests, often scoring better here than they do in the
highway cycle: when stopped at a theoretical stop light, they aren't using any fuel at all.

The fuel economy gains aren't as high for something like this as for a full hybrid, but neither is this system as expensive or complex.
We'll get into the financial impact of hybrids below.

As usual, the financial worthiness of a hybrid involves some math, which we will get to shortly.

In practice, the Saturn Aura Hybrid is perhaps the least weird-feeling vehicle in the hybrid field.

It looks normal on the outside, apart from subtle badging, and inside it is almost identical to the regular Aura, apart from a
couple of unique gauges on the dash.

One of those gauges is the Charge/Assist gauge, which tells you which way electric power is flowing – either to the front wheels
or to the battery.

There is also the ECO light (in green, what else?), which glows when the car is operating at its peak efficiency.
Part of the fun in driving this car is to keep the gauge pointing at "charge," and the little ECO light glowing cheerfully.

In operation, there is a small shudder as the engine stops and restarts, but there are none of the extra whirrs, wheezes and
whines you hear in most hybrids. In the Aura, you turn it on, push the right pedal, and drive.

The main motive source is a 2.4 L twin-cam 16-valve four-cylinder – essentially the same as powers the base Aura,
but retuned to produce 164 horsepower, 5 less than the conventional car.

It drives the front wheels through a conventional four-speed automatic transmission.

The hybrid operation is virtually seamless, although if you're running at around 80 km/h and want to toe in just a touch of
extra power, the car seems reluctant to respond.

Hammer the pedal down and off you go, decently briskly.

Despite being quite large in displacement for a four, this engine runs smoothly and quietly: Saturn has added more sound
deadening materials into Aura than most cars in this class.

There is some road noise, at least partly due to the low rolling resistance tires Saturn fits to the Hybrid variant, but it's not
objectionable.

The suspension is European-influenced, hence firmer than usual for a domestic car. This translates into a confident ride and
stable handling. The electric steering is particularly nice.

Other Aura Hybrid road-testers have commented that the regenerative braking tends to feel unnatural – you just lift and the
car starts to decelerate faster than engine braking alone would do.

I can't say I really noticed it, although I did find the brake pedal too hard; it needed quite a shove to get the car stopped.

There's loads of room inside this car, front and back. Even the trunk is decently sized, which is another advantage of the
mild hybrid, whose batteries tend to be smaller than those in full hybrids.

The seats are comfortable: I drove down to Detroit and back on consecutive days and arrived at both destinations nicely
refreshed.

Now, about those financial calculations. Transport Canada's little black book says the Aura Hybrid will cost $1,350 for fuel
per year, while the regular four-cylinder Aura runs you $1,476, an annual savings of only $126.

This assumes 20,000 km of driving per year, a mix of 55 per cent city and 45 per cent highway and a price for a litre of
fuel of 90 cents – if you find any of that, please let me know.

Applying a more realistic fuel price ($1.10) those numbers become $1,650 and $1,804 respectively.

One hundred and fifty-four bucks a year. Forty-one cents a day. Big deal.

The Hybrid costs $3,355 more than the regular base car ($27,575 versus $24,220).
So it will pay for itself in only 21 years!

So, the chances of the Aura Hybrid ever justifying itself on an economic basis are slim to none.

Of course, there are other reasons for buying a hybrid. In the Aura's case you'll emit 336 fewer kilograms of carbon
dioxide (3,936 versus 3,600 kg annually) into the atmosphere with the Hybrid. Is that worth three grand?

You may also want to feel you're "doing something for the environment" by boasting about your greenie car.
But it's a marginal boon to the environment even so.

If you want to do something for the environment, spending $3,355 on more insulation for your attic is probably a much wiser,
much greener strategy.

PRICE: $27,575

ENGINE: 2.4 L four cylinder

POWER/TORQUE:

164 hp / 159 lb.-ft.

FUEL CONSUMPTION:

city 8.5; hwy. 6.2.

COMPETITION: Nissan Altima Hybrid, Toyota Camry Hybrid.

WHAT'S BEST:

Probably the most conventional hybrid you can drive.

WHAT'S WORST:

Fuel savings not as good as full hybrids; additional cost of hybrid

WHAT'S INTERESTING:

The easiest way to ease into the world of hybrids, if you really feel you HAVE to.