Imagine driving almost 1700kms in a top-end luxury car ... trying not to touch any of the whizzy comfort features that make it so special, for fear it might affect the economy.

It's par for the course in the AA Energywise Rally, an economy run that ended in Auckland last night.

Travelling economy style in business class possibly helped the generously-appointed BMW 730d and Hyundai Grandeur diesel sedans respectively achieve 8.2 litres per 100km and 7.2L/100km. Not bad returns given their size and weight.

Yet their crews travelled in discomfort for naught. They were still beaten ... by a petrol V6 Honda Accord. The cylinder deactivation model achieved a 10L/100km average.

How does that happen? It's a familiar story to those who know the history of the big four-day Auckland to Wellington and return economy run.

As in past years, results are not based on fuel burn alone, but also running costs. The object is to finish cheapest.

The diesels burn a cheaper fuel more efficiently but, once the road user charge is taken into account, they're pretty much scuppered nonetheless. The BMW favoured by the Government for its efficiency never stood a chance. The Hyundai pair almost cracked it - the difference in cost per kilometre between their car and the Accord came down to 0.1 of a cent.

So it mattered not that more diesels than petrols contested the race. After 1620kms of (sometimes sweaty) softly-softy driving, more petrols than diesels won prizes.

A VW Polo with a three-cylinder thrift-optimised diesel went furthest on the least fuel, with a 3.6L/100km overall. Yet it could only win the environmental award, for lowest CO2 output. To me, that's an 'also-ran' prize of limited merit.

The supreme award went to a Civic hybrid that averaged 4.7L/100km. Honda's petrol-electric was always a dead cert; only it and Toyota sell that technology here and the latter had ignored the competition this year.

The 2.0-litre Mondeo TDCi auto sedan I drove was never in the hunt, even within the medium-executive category.

As I'd expected, the manual diesels in our well-subscribed class achieved more while drinking less. No more so than our class victor, a VW Jetta BlueMotion, which allies lean-burn engine technology with a tall-geared manual transmission and low rolling resistance tyres.

We probably paid a price for driving too fast - though rarely above the posted speed limit - for keeping the cabin chilled on occasion and, in all probability, for daring use the stereo. Oh, and the indicators when we turned, the wipers when it rained and the lights when it seemed prudent. I know of at least one other entrant who did not. Team orders (he claimed).

No such silliness with Ford. Despite such recklessness, with an overall average consumption of 5.9 litres per 100km, 'Rep One' bettered the claimed overall consumption for a Mondeo diesel by 19 percent. I was happy with that.

Indeed, all the Fords beat their targets - the 1.6-litre Focus was eked out to a 6.7L/100km average, while the Falcon XR6 achieved a stunning 22.4 percent improvement, with a burn rate of 7.9L/100km. Whoever says big Aussie cars aren't thrifty should consider this result.

Don't think it's a given that every entry shows improvement. Eight of the 60 cars entered failed to meet the maker's claimed returns - including, would you believe, both Civic hybrids.

On the other hand, the vehicle that in 'normal' use would surely be least parsimonious - the Holden Special Vehicles' Maloo R8 ute - was a winner on the night, taking a 'best driver' award.

Actually, make that best drivers - eight TradeMe staff took turns to keep the 6.2-litre V8 beast under tight control. The lightest right feet in the rally pinned a car rated at 15.7L/100km down to 9.5L/100km.

So, what did we learn? Personally, the experience affirmed what an amenable long-distance travelling companion the Mondeo is.

The entry model's utilitarian presentation masks a car of real quality. It goes the distance insofar as comfort and dynamic ability are concerned - on every road we encountered, it really was a delight to drive, with sharp, accurate steering and compliant suspension. Surfing that big wave of sub-2000rpm torque was a pleasure, too. And it was great to step out after eight hours at the wheel without any lingering aches.

Economy-wise, I'd also contend it also passed the test. There was huge satisfaction in achieving sub 5L/100km consumption while still holding pace with everyday traffic. On the flattest, smoothest roads, we were sometimes in the low 3's. That's cheap, effective motoring.

It might have done better had we driven more carefully. But we set out to tackle this real world drive at real world pace and did just that. Not everyone could claim the same.

Despite the organisers' best efforts to ensure a reasonable pace, there were still a few who ran a slow race. Some collected prizes. At least one went home in a huff. A couple probably caused unnecessary headaches for regular road users or severely frightened their co-drivers.

It's a shame the diesels don't get more credit, simply because this is the fuel and technology that makes more sense to more drivers, particularly those regularly running long distances. Virtually every diesel in the rally ran frugally by real world terms (one exception being the car driven by a newspaper hack who simply wanted to be first home on every leg) yet, of course, that still wasn't good enough.

The next rally will be in 2010, and by then the Civic hybrid will have been replaced by the Insight and Toyota will have a new Prius. As the rules currently stand, only those cars have a chance of winning the only award that matters.

You may wonder why makes without access to such technology would want to compete in a two horse race, yet perhaps they still will.

After all, this year there was record support for a race in which only one car had a chance of true success.

What this means to you:
Same old story as two years ago. Hybrid wins the race, diesels win with true drivers.