General Official MPG vs Actual

Discussion in 'Lounge & Gossip' started by ArcticFire, Sunday 20th Oct, 2013.

  1. ArcticFire Club Veteran ★ ★ ★ ★ ★

    Scotland Graham Scotland
    So my mate's been having issues with his brand new Vauxhall Astra in that it's returning 45.5mpg with his driving being a short stretch of dual carriageway and then motorway for 40 miles and everything in the car turned off (A/C etc). The official figures are:

    Extra Urban: 70.6mpg
    Combined: 62.8mpg
    Urban: 52.3mpg

    So he's not even getting the urban figure! He's been back and forth with Vauxhall and just the other day they came back to him and said that it's allowable for real MPG to be up to 50% less than the official quoted figures :Aghast:

    What's your thoughts on this? Doesn't seem right to me.
  2. TheDarkKnight Club Veteran ★ ★ ★ ★ ★

    Seriously - what does he expect - its a "Vauxhall".

    Many new cars never reach or get close to their advertised MPG. Your mate is a fool for not having a long test drive to check for himself what the car could actually achieve before buying it. No sympathy here I'm afraid. His first mistake was to buy a Vauxhall - his second mistake was thinking Vauxhall give a damn - because I bet you they couldn't give a monkeys.

    Plenty of car makers miss their real world MPG targets - this is not a new phenomenon. Your mate needs to get out more frankly and discover that.
  3. FirstHonda Moderator Staff Team

    United Kingdom Ed Wiltshire
    A colleague of mine bought a BMW X1, and had the same thing - actual economy was miles away from the official figures. After a few dealership trips they declared it "within acceptable limits." So he doesn't drive a BMW any more...

    I think this is an issue for lots of cars/manufacturers as the official figures are obtained in an "ideal" environment. What Car? magazine do their "true MPG" tests on some cars, and nearly all are well below the official figures. There ARE some exceptions though from memory.

    They haven't tested the Astra by the looks of it, but they have tested a couple of Honda models:

    Civic 2.2 I-DTEC - true MPG 59.0 vs claimed MPG 67.3
    CR-V 2.2 I-DTEC - true MPG 36.3 vs claimed MPG 48.7

    Not sure what they use for the "claimed MPG", I guess the blended "combined" number.
  4. ArcticFire Club Veteran ★ ★ ★ ★ ★

    Scotland Graham Scotland
    I'm guessing that because they all have to use the exact same EU regulated test then some of them are choosing to use the legal loopholes to improve the figure? Otherwise all cars should technically suffer the same drop in real world performance when brand new.

    I did advise him against a Vauxhall but the interest free finance (which we all know is recouped through the price of the actual car etc) and 100,000 mile warranty appealed as he needs the car for work. In retrospect he's kicking himself. I've noticed that it seems to be diesels that overstate their official MPG and petrols seem to be more accurate. Perhaps petrols maintain their efficiency better over time?
  5. TheDarkKnight Club Veteran ★ ★ ★ ★ ★

    Not all diesels overstate their MPG.

    On my 8th Generation Accord, I was regularly achieving 65-75mpg. On my new 4th Generation CR-V, I am getting 65mpg on the m-way and can even get 50mpg on stop-start runs!
  6. i-DSI Club Veteran ★ ★ ★ ★ ★

    Belgium Aalst
    Hi Arcticfire,
    I'm doing better with all cars I've owned in real life MPG compared to official figures. Independent what brand or fuel.
    It all comes down to the drivecycle circumstances you're facing and I've never seen any manufacturer stating that you will achieve the official figures.
    The official figures only serve to make it possible for customers to compare several cars with each other. A car showing 40 MPG will 'most likely' need more fuel than the one showing 45 MPG.... But on short driving cycles other things might come in to play: how fast does the engine get warm, did you need to stop once, twice before traffic lights, ambient temperature etc....
    For my Accord 2.0 i-VTEC I need between 6,2 and 6,8 l/100 km. Official mixed figure: 7,2l/100 km.
  7. Doc Club Veteran ★ ★ ★ ★ ★

    Matt Peterborough
    It's got nothing to do with it being a Vauxhall it's an industry wide problem. Despite recent changes to the way MPG figures are measured there still seems to be a huge disparity between stated and actual figures.

    My advice is do your research before buying a car. Get reviews from forums of actual drivers experiences instead of being seduced by the glossy brochure. He's only got himself to blame for not doing his research.