Jacqui puts the new Holden Commodore to the test on State Highway One to see if it will go the distance on a tank of gas
Is there any point doing a fuel economy run? After all, what an individual will achieve depends not just on how efficient their car is, but on their driving style, where they live, and how much city or open roading they do.
Official figures do at least provide a point of comparison - they're measured in a laboratory, so on a level playing field.
But punters often complain they can't match those figures. Which is why many car companies enter the biennial EnergyWise rally (returning this November) or conduct their own runs.
Holden has a bit to prove. It's introduced direct fuel injection to its Commodore sixes, but the message is taking a while to get through. The current Omega has a 9.3l/100km claim - considerably better than its 10.7 predecessor. But is it a realistic figure?
I averaged 9.5 during a week with the car, and though I'm semi-rural my drive traverses steep hills via narrow winding roads - fairly demanding territory. A Manawatu-based colleague claimed 9.7 including highway. I can't speak for him. I was driving as I normally would, with a few fangs to make the most of the car's nicely-balanced handling, and a bit of cruising when appropriate.
Holden's Fuel Challenge would take us as far down highway one as we could go. Highway cruising is far more efficient than round-town stop-starting of course, and an instant fuel-saver if distance-to-litres is all you're after.
But Highway One is far from a doddle at times. It includes towns and traffic lights, road works, 35kmh corners, and ferry queues. I know from past experience that you can't expect much above an 80kmh average, assuming minimal toilet stops and 100kmh wherever traffic and conditions allow.
And that was Holden's rule. An 80kmh average, air con on, no turning the ignition off at stops, follow the road rules, use cruise control on the flat.
Five cars - one driven by Shane Hart, who'd won a Facebook contest to join us. Two 3.0-litre Omegas, a 3.6-litre sedan and wagon, and the top-spec 3.6 Calais with Shane at the wheel.
Auckland to Taupo via Matamata (7.7 average) was mainly conducted with cruise control set, but it wasn't much use down the lake, with its heavy traffic and speed-limited bends, or on the long climb to the desert road where roadworks delayed us.
We sat mostly in auto, using manual shift for optimum revs on the steeper bits, and otherwise relied on a light foot - and anticipation. Looking ahead, working out what the road and traffic are doing to assist the most efficient approach; it's also a safe way to drive. By Bulls and 7.5 we'd got into stride, the run into Wellington on 7.2 thanks to luck with lights and light evening traffic.
The ferry queue was a killer - this is where stop-start tech pays off - and we were into the long haul out of Picton, then into the teeth of a southerly gale, cruise set at 98kmh on the flats (a speeding ticket would have been embarrassing).
We were first into the Christchurch Holden dealer, still on the original tank, at an average of 79.57kmh and 7.6l/100. The 3.6-litre wagon averaged 78.56kmh and 8.1l/100km.
Not earth-shattering, but it does prove a Commodore will now do the distance on a tank; that even large engines can be efficient; and that how you drive can save you money at the pump.
Photographs by Augusto Creative Media.
See new Holden Commodore for sale here.