2010 Holden Commodore AFM Car Review

When you're a motoring journalist and testing so many cars all the time, you have to keep on top of things, like actually noting down which car you are due to actually pick up. That means a booking calendar which often looks like the scrawling of a mad scientist rather than anything else.

So when I saw that I was picking up an 'AFM' I realised that I'd made a slight stuff up. Usually I use the full name of the car. This time it was a bit of a mystery. For all I knew I was due to pick up an Angry Furry Monkey, or perhaps an Alternate Fuel Monorail.

It was of, course, Holden's Active Fuel Management system, which is now standard on all V8 Commodores. Now, most people think of fuel efficient cars in the form of hybrid vehicles such as the Toyota Prius, which uses a hybrid drivetrain, but like Honda's latest V6 Accord, this Commodore switches off cylinders when power is not required.

And that essentially means the engine is a V8 - except when it's a four cylinder. This technology has been in the GM stable since around 2007, but has only now filtered down to the lands down under. The AFM system is claimed to save up to 1.0L/100km depending on the conditions in which the car is driving, but in town it seems to work even better than that.

The upshot here though is that, unlike all the other hybrid systems out there, you have a big stonking 260kW 6.0 litre V8 on hand when you want to make some noise and accelerate rather quickly. And yes, the noise and acceleration are rather addictive.

But drive more sedately and you'll find that the AFM system works quite well. There's a little indicator on the dashboard that tells you whether you are in four or eight cylinder mode, and even when you're on the open road at speeds the 100km/h speed limit and 'possible' speeds higher than that, the system will still switch into four cylinder mode when you don't need the extra power.

This is important, because cars such as the Prius are solely designed for stop start urban traffic. When you drive a Prius on the open road the engine is on all the time and your fuel consumption increases dramatically over the claimed figure. That's not to say that the V8 in the AFM Commodore uses less fuel than the Prius, but that it is more suited to the more rural setting of New Zealand than the congested city centres of Japan.

And the downside? You can feel when the engine switches from eight to four cylinder operation through a change in engine note and a slight increase in vibration from the engine, but unless you spend your life evaluating cars I challenge you to actually tell the difference.

The best thing about the AFM Commodore though, is that since the engine operates on two such different modes the distance to empty readout on the trip computer often doesn't know what to display. You'll go from 160km to 240km to 120km within five minutes, all depending on how you drive and what traffic speeds you encounter.

But in the end the system makes a big, powerful throaty V8 sip petrol more like a moderately sized V6, which can only be a good thing for everybody.