Why we need to get real on MPG - and pay more in tax if we have to
* The latest 'real-world' results from Peugeot presage big shift in measurement of fuel usage
Real-world fuel consumption could be a double-edged sword for car buyers who so often find huge differences between claimed and actual litres-per-kilometre .
New ways of testing consumption will give a far more accurate idea of what the car they are going to buy will consume.
But be careful what you wish for as it is almost unavoidable that the tests will lead to a rise in purchase and road tax.
That is because they are going to reflect higher fuel use and greater emissions of C02 than current 'official' figures. Emissions, as you know, determine how much Vehicle Registration Tax (VRT) and road tax you pay to buy and run a car.
I think there may be no escaping increases even allowing for carmakers bringing levels of C02 down to historic levels. The current testing system for fuel consumption is beyond redemption and only serves to reveal the massive disconnect between what people are being told and what they are discovering themselves behind the wheel.
There are a few exceptions but in the main people have lost faith in the official figures.
A new way of doing things and measuring consumption will soon be with us - and not before time. Meantime car companies are realising they might as well reap whatever benefit the ill-wind brings by carrying out their own real-world tests in advance of official new procedures.
Peugeot would claim to have stolen something of a march by forging ahead with their tests; a few months back Motors reported on the results of independently vouched MPG for the 308 model.
And just recently they unveiled figures for the 2008 SUV.
They show in no uncertain terms how much of a gap there can be between quoted and real-world fuel consumption.
When I asked a senior executive about the implications for buyers and car makers, he was honest to the point of bluntness: new ways of measuring are coming anyway so it is as well to show buyers now as later.
Here is just one example. The Peugeot 2008 1.2-litre PureTech (82bhp) 5spd manual version has official figures of 4.9litres/100km (57.6mpg). However, those driving the car on a 90km route embracing rural and urban traffic, got 6.3litres/100km or 44.3mpg - a notable difference.
Peugeot used a mix of professional and amateur drivers who were not directly employed by the company. It intends showing real-world figures on all models in the future.
Three non-governmental organisations helped organise and oversee the procedure.
The PSA group, of which Peugeot is a member, insist that the test is reliable but obviously elements such as driving style, temperature and wind strength can't be controlled as they are in official laboratory trials.
What do you think?
Would you pay more for a more realistic outline of what your car will consume?