Official fuel economy tests on new cars are being fixed by car makers using a number of legal ‘tricks’ that artificially boost economy ratings.
In fact, we usually find car makers’ figures are out by anything up to a third when we have a car in for review, and they are really good for nothing except vague comparison between different cars.
Now it seems that it’s not just the fact that economy testing isn’t done in the real world that makes the figures so wrong, but that car makers are going to extreme lengths to ‘improve’ their figures and give them an edge.
A report from the Transport & Environmental Campaign Group claims car makers are overstating economy by at least 25 per cent and in some cases as much as 50 per cent (interestingly, the SMMT reported only yesterday that new cars are now 25 per cent more economical than cars from a decade ago).
Manufacturers are using a variety of tricks to improve their figures, including taping up panel gaps for improved air flow, using super slippery lubricants, disconnecting the alternator, changing wheel alignment and pulling brake pads off the discs, over-inflating tyres and testing at high temperatures.
Astonishingly, the system is so lax that all these ‘tricks’ are completely legal, so it’s no wonder official figures seem completely false.
We’ve long called for official economy testing to be done in the real world by a completely independent body, and the report from T&E shows how necessary this is. And at the same time we should be focusing on and taxing NOx and particulates rather than CO2 (although CO2 emissions are just an extrapolation from the official mpg anyway).
It really is time to make the official economy tests useful.
Marce says
there is lot of things which is good but the eoconomy figures are nor right they must be taken as per asumption but than too it has some important points which are usesful.
AudiMan says
Another common trick is to test a car only when it’s fully warmed up – not the ‘real world’ start from cold. My own car averages about 45mpg overall. But for the first mile of the day, the trip computer says it does only 30mpg!
Percy says
Does anything ‘official’ ever tell the truth?
M1TCH says
No mention here of ‘removing rear seats’, or ‘fitting narrower width tyres’, both of which I understood were common practice?
Cars UK says
Nothing would surprise us.
Tramp12 says
We’d be better off completely scrapping official figures if they’re are this manipulated. Just let car makers advertise what they say we will get and then we can sue them when we don’t get close!!
PhilipJH says
What a shock (not)!
SimonSez says
If economy figures are so fake they’re actually worse than useless. This must be bordering on fraud.