Why mpg dreams can be shattered by high fuel bills
Row rages over consumption claims by manufacturers
I AM regularly upbraided by drivers for publishing car manufacturer figures on fuel consumption. People tell me they are out of the ball park. I always insist these are 'claimed' figures.
But there is no doubt the means by which they are obtained are strikingly at variance with the real-life experience of drivers – including myself.
Indeed it is being claimed that fuel bills could be up to 25pc higher than these official test-based results indicate.
The critical thing here is the link between consumption and emissions. In the current tax environment, lower consumption means fewer emissions. And that means lower taxation – so the price of the car comes down.
For example, a car that officially emits a combined 110g/km may, in reality, only ever manage 125/130g/km for a whole variety of reasons (not least because of the way it is driven). But as far as the authorities who level the tax are concerned the official 110g/km is the only one they are interested in. So long as it has been arrived at through the approved testing procedures, there is no problem.
But it is those very procedures that are increasingly being questioned – smooth surfaces, super-efficient tyres etc all reduce fuel consumption in an ideal world.
It is all topical again now that European figures are showing that official carbon dioxide figures for new cars sold in the region last year dropped to 127g/km – that is equivalent to an average of 56.5mpg. Officially it means carmakers have beaten the 2015 target to cut the average to 130g/km.
But according to many, including the Brussels-based Transport & Environment (T&E) group which represents 50 organisations across Europe, this is nothing like what owners achieve in real-life driving. The group reckons the truth is closer to 45mpg.
Here's what they say: "Fuel efficiency standards are being undermined by an obsolete test. The test procedures are a Swiss cheese, full of loopholes, that carmakers exploit to exaggerate improvements in fuel economy and emissions."
But carmakers respond by saying that the laboratory conducted tests are important because they give buyers a reliable comparison between cars.
But T&E say the so-called loopholes mean motorists can't compare rival models. Have you a car that is measuring up to its claimed mpg? Or is it falling below it? Email me.