It’s a dilly of a pickle alright. Don’t mention the F-word (fuel) but it’s more expensive than ever before, and will probably continue do increase in price until the taps get turned off for good. Add into that the vehicle excise duty charges that punish you for having a thirsty beast and the inevitable result is that fuel consumption is becoming a factor that everyone is giving extra consideration to.
Trouble is the official government fuel consumption figures have now come under scrutiny, and this has opened a catering-sized can of worms. Leading the rumblings is What Car?, which has launched its ‘True MPG’ initiative, as Editor Chas Hallet explains:
“With rising fuel prices, the miles-per-gallon issue is high on every motorist’s agenda. Countless car buyers are frustrated that they don’t match the official government fuel figures. True MPG will allow motorists to select a car personalised to their driving needs and budget. We hope that it will become invaluable in the complex and emotional car-buying process.”
So far, so good right? Well not necessarily. Firstly you need to know that the official government tests are carried out on a rolling road – essentially a set of rollers that you park the car on and drive it so the engine runs and the wheels turn but it doesn’t go anywhere – to give conditions that can be perfectly reproduced over and over again to ensure consistency.
Of course, the problem with this system is that it isn’t particularly representative of real life; there’s no traffic, no wind resistance, no weather conditions and so on. Plus the car manufacturers have sensibly twigged that a car can be optimised for these specific conditions to achieve spectacular results. That might sound like cheating but it’s the same conditions for all, so it’s not really unfair.
However some owners are miffed that they can’t get anywhere near the official consumption figures, and the What Car? data is showing a consistent under-achievement in its ‘True MPG’ figures compared to the official data. And in truth that is to be expected.
But the problem with any kind of ‘real’ MPG data is that it can never ever be consistently reproduced. Even if you conducted tests on a closed road with no other traffic, ambient conditions can have a dramatic effect on consumption – wind creates drag or can even help if it’s blowing in the right direction, and temperatures affect both engine power and efficiency. Even the time of day can make a difference.
But more importantly than that, the official consumption figures can be achieved or even beaten. Every year the Fleet World MPG Marathon sees a huge variety of production cars taking part in an economy test, usually well over 350 miles on a variety of roads. The prizes are awarded to the cars that beat the official combined figure by the greatest amount, and pretty much every car will do that by some margin.
What no-one will tell you is that you have to drive as if you’re starring in your own version of the film ‘Speed’, except that the bomb goes off if you accelerate too hard. Economy driving requires skill, delicacy, anticipation and an acceptance that it will take bloody ages to get anywhere.
It doesn’t matter what car you drive, you can smash the combined figure if you really try. You just need a lot of time and patience to do it.