Which!!! cars are least like their published fuel economy figures?

16 June 2015

graph by which!!!
graph by which!!!

As anyone who’s ever internet dated will tell you, sometimes people oversell themselves and once you take them out for a test drive, you realise that the performance just isn’t there. It’s the same with cars- you politely check the MPG rating before you buy, but then find you’re being taken to the cleaners on fuel consumption once you’ve parted with your cash. But which car manufacturers are the best (or worst) at overestimating their medium-sized cars’ efficiency? Which!!! decided to find out.

EU law requires manufacturers to show official test figures in their adverts to help consumers compare fuel economy between different models. But Which!!! think some of the MPG figures quoted are unachievable by normal people. And they don’t like that at all. The EU test is due to be updated to a more accurate test in 2017, but some car marques would like to see this delayed until 2020.

Now, before you start thinking that the guys in the Which!!! office just went out on a load of jolly test drives, they claim to be trying to get “the most accurate picture possible” of how cars perform in actual everyday life. So when assessing fuel economy, unlike the official EU test, Which!!! included a motorway driving simulation, and they switched on all the lights and had the air con blasting. They didn’t mention whether they were also playing some tunes. Also, if a car has different driving modes available, Which!!! used the start-up mode, rather than any Eco mode as “this may offer better economy, but will also often neuter a car’s performance to the point where it’s awful to drive.” Fair point.

And the results are interesting. The ‘medium cars’ category is an industry-standard class which includes cars like the Ford Focus, Audi A3, Peugeot 308, Seat Leon, Volvo V40, Volkswagen Golf, Alfa Romeo Giulietta, Renault Megane, Mercedes-Benz A-class, Honda Civic, BMW 1 Series, Hyundai i30 Tourer, Skoda Rapid Spaceback and Kia Pro-Cee’d. Which!!! found that medium-sized cars from the likes of Audi, Volvo and Alfa Romeo were actually more than 10% less fuel efficient than the official MPG figures used by manufacturers in their advertising. Audi came top (bottom) of the chart with a whopping 15.3% difference in MPG figures. Hyundai cars were the closest to the published figures at just 1.5% away.

In fact, Which!!! found only five medium cars– Hyundai (-1.5%), Kia (-2.3%), Honda (-2.8%), Skoda (-3.6%) and Mazda (-4%) –  that came within 5% of the published MPG figures when compared with the Which!!! test.

Of course, Which!!! aren’t claiming that the manufacturers are lying or even misleading the public with their figures, those MPG figures were probably genuinely obtained in a lab somewhere. However, Which!!! believe that the current test’s “lack of real-world driving scenarios and numerous loopholes” mean that the headline figures are just a pipedream for anyone actually driving a car in real life.

TOPICS:   Motoring


  • Joe
    Wonder why theres no citroën
  • Censorship a.
    It gets worse, most cars are set up to over-read speed and distance by 10%, so the real MPG is often 10% WORSE than the dismal figures given. I am lucky, although my car is incapable of reaching the MPG given for motorway use, I regularly beat the "Urban" figure and get very close to the "Extra-Urban" figure (sometimes a bit under - sometimes a bit over). This is after using GPS to calculate how far out my cars speedo and odometer are.
  • Oli
    it probably broke down during the test
  • Big A.
    No Toyota either? Or am i bei ng a bit blind

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