Cars' mpg figures may not be all they're cracked up to be

4 April 2013

TOPICS:   Motoring


  • SysOp
    Seeing as MPG figures are calculated in highly scientific off-road laboratories, is it any wonder why MPG claims vary significantly? A pinch of common sense please.
  • Captain.Cretin
    Except you are not supposed to do that as it can bugger up the catalytic converter. It has been a looong time since I owned a vehicle that I could reach/exceed the official mpg figures (Audi100 Avant 2.2CD from 1982 and Skoda Felicia 1.3 from 1998), even at 50mph on a long, clear motorway run (M5 from end to end and then back again in the middle of the night).
  • Adam M.
    Still running a 'new' 1997 Peugeot 306 1.9 Turbo Diesel. Its pretty much as good today, as the day I bought it from new, for motorway fuel economy. Tick over has never budged. No fancy electronics to go wrong, passes its MOT every year. Cheap as chips to run, both insurance and Diesel. I still like the sharp angled look of it, compared to modern cars. A classic bit of engineering, the Peugeot Diesel Engine.
  • Grammar N.
    Wasn't this (or an almost identical story) posted on here a month or two ago?!
  • Grammar N.
    Yes, similar though a different source/piece of research -
  • Mike O.
    @Grammar Nazi I thought that to.
  • Grammar N.
    It was, in January - I tried to post the link but its awaiting moderation.
  • chewbacca
    @Grammer Fascist They don't like links on here. And "awaiting moderation" actually means that your comment has disapppeared forever.
  • Zeddy
    Whatcar is a pile of self-righteous crap who loves the HUN (VW group). Try Honestjohn website to see what motorists get themselves.
  • Mr M.
    @ Adam Mason As a previous 306 owner I'll agree they made a cracking engine, but even if they didn't have fancy electrics to go wrong, the bog standard electrics were a disaster waiting to happen. I now own a Mazda 3, so I guess I should be pleased that science has proven I'm a winner.
  • Stu_
    as someone who has a Prius as a company car, it doesn't hit anywhere near the 70mpg that Toyota reckon. The real MPG calculator is scarily accurate around 55mpg.
  • Han S.
    @Grammar Paolo Di Canio "I thought that to." - Surely you mean 'too'?
  • Alexis
    Not sure how you can test cars other than in a lab. You'd need identical weather conditions for a start. Manufacturer X would complain the temperature was a degree out on their day. They're a comparative tool for engines and gearing, not a true MPG indicator. The only problem is that manufactures tailor the ECU mapping to excel at the test.
  • Grammar N.
    @ Hans Solo - I think your question was addressed to the wrong person. Yes, he did mean "too".
  • Stu N.
    I think there's shared blame here. Car manufacturers definitely cheat in the economy tests, taping over panel gaps, overinflating tires and doing anything they can to make the car lighter and more aerodynamic. However, most drivers don't drive like they're on an economy run. Supermini drivers (mostly young people, no kids) especially are likely to give the car a bit of a boot. Claimed MPG figures may be unobtainable, but you can't expect to get close if you drive like a right Clarkson all the time. The one upside to car manufacturer's cheating is that the cars produce fewer emissions in testing than in real life - but VED bands don't realise this. Your 0.9 litre petrol may claim 65mpg and 99g/km CO2, giving free road tax, and if in reality you're only getting 40mpg and 130g/km, your road tax is at least still free.

What do you think?

Connect with Facebook, Twitter, or just enter your email to sign in and comment.