Fuel costs have never been so alarming for motorists as petrol prices break the £5 per gallon barrier for the first time.
But things aren't going to get any better in the short term, so we might as well make the best of what we've got. That means trying to wring every available extra mile out of a gallon of fuel – and maybe thinking a little bit more about the way we drive.
To find out the best way to do this in everyday driving, motoring editor Alan Candy visited Millbrook's Proving Ground near Bedford at the invitation of BP, where a green driving challenge with a difference awaited.

After I'd made a mistake going up a truck slope, it was all downhill from there on when it came to fuel-saving.

I was doing pretty well at the wheel of a Ford S-Max, trundling the assortment of artificially-created roads around Millbrook.

Trying to keep on the move, smooth gear changes, easy on the brakes, no coasting downhill in neutral, all that sort of thing.

My classic boob was to think my faithful 2.0-litre Ford could make it up the hill in second gear. It couldn't, and I was forced into a humiliating change down to first before trickling to the top. That wastes fuel, folks.

And, unleashed on the six-lane, high-speed bowl, I couldn't help but enjoy a little unfettered 70mph driving, sending my petrol consumption temporarily crashing off the scale.

Before that, everything had gone pretty well as I tackled Millbrook's virtual 'outer handling' area (basically like B roads), city circuit, roundabout and truck slopes (up and down), hill route, ski-hump and link roads.

They're all designed to mimic in miniature the sort of roads we drive on every day in the UK and to make sure it's pretty realistic, drivers tackling the circuits have about eight separate stop points, so you can't just keep moving happily along.

That's why so many manufacturers head for Millbrook to test pre-production prototype cars under a variety of conditions (there's also a knobbly suspension test area) as well as in the on-site labs.

Computer analysis of my 25-minute drive showed some eye-opening results after all the numbers had been crunched.

In the BP Ultimate Green Driving Test, my drive was translated as a rather shocking graph indicating both my Real Time Fuel Consumption and Fuel Consumption Accumulation, with a frightening final print-out of my efforts.

The engineer who had achieved what was regarded as "the perfect run" had recorded 34mpg overall, and that was the figure to beat. So why had I only achieved 20.95mpg? Well, those hills and that fast bowl run had done for me.

But the on-board instructor also told me that better forward planning would have helped, as would less hard braking, maintaining momentum and keeping the car at its most efficient throttle and revs – that's between 2,000 and 3,000 on the rev counter.

Coasting in neutral downhill to save gas? That's an old wives' tale. Foot off the pedal means free travel downhill but if it isn't in gear, the engine has to drive itself and uses fuel.

And here's a stat to fret over – in order to double your speed, you use four times as much fuel, according to the laws of aerodynamics. The 21mpg and 34mpg disparity may not seem too drastic.

But BP points out that the fuel costs over 10,000 miles
would be an extra £916.07 from my bank balance and my emissions would be an extra 1,915kg of CO2 over that distance. Gulp. Believe me, I drove home very gingerly that day...