Top 10: Cars that fall shortest of their claimed MPG
While it has become the accepted norm that a car will never match its claimed MPG figure, there are some cars that fall way short of what the manufacturer claims. The gap between the official figures and the economy people are actually seeing has widened over the past years.
These then, are the cars currently on sale that fall shortest of their claimed MPG figure. As Real MPG is a live database, these figures will change over time. We have used models that have at least 50 Real MPG submissions.
Mercedes-Benz C 350 e - 46.3mpg = 38% of its claimed MPG
The headline figure here looks pretty awful, with the plug-in hybrid version of the C-Class getting nowhere near its claimed economy. But the C 350 e is a victim - if you can call it that - of the woefully inadequate NEDC test. A test that only covers 11 miles and is carried out in a laboratory. Due to the fact it's a plug-in - and running for electricity for the majority of that test - its official figure is 122.8mpg, hence why it falls so short.
Mitsubishi Outlander 2.0 PHEV - 62.6mpg = 42%
The second plug-in hybrid in our list, the Outlander PHEV is actually an economical car with owners seeing more than 62mpg - an impressive figure. The problem comes when you compare that to the official economy. Like the Mercedes C350e, the Outlander suffers because of its high claimed figure - in this case a ridiculous 148.6mpg - due to the inadequacy of the NEDC test.
Kia Cee'd 1.6 CRDi DCT - 40.5mpg = 58%
Kia models seem to be somewhat hit and miss when it comes to Real MPG figures. On the whole, the diesels perform pretty well in terms of matching their claimed figures, but that's not the case with the 1.6 CRDi engine when it's fitted with the newer seven-speed DCT dual-clutch automatic, which sees it fall considerably short of its claimed economy.
Fiat 500 0.9 Twinair 85 - 46.8mpg = 65%
We have received many complaints over the years from owners of Fiat Twinair models regarding its poor economy, so it's no surprise to see it feature here. Again though, this is all about expectation. More than 45mpg is not bad at all for a small petrol city car, but when you're promised more than 70mpg, you're clearly going to be disappointed.
Ford Focus 1.0T EcoBoost 100 - 41.9mpg = 66%
Few of the different EcoBoost engines in the Focus range perform well here, but it's the lowest powered 100PS version of the 1.0-litre turbocharged engine that misses the mark by the biggest margin. Overall, it's not actually proving that much more economical in real world driving than the 125PS or even the 140PS versions of the same engine.
Land Rover Discovery Sport 2.0 TD4 180 Automatic - 35.8mpg = 67%
No model in the Discovery Sport range manages to achieve more than 70 per cent of its official economy figure, but the worst offender is the automatic version of the more powerful TD4 180. Despite a claimed figure of 53.3mpg, owners are seeing less than 36mpg. Disappointing, to say the least.
Toyota Prius Hybrid - 63.6mpg = 68%
Like the Outlander PHEV, the actual economy figure of the Toyota Prius is actually very good. Most people would be happy with a family car that's quiet, comfortable and can do more than 60mpg. But when you're promised a pie-in-the-sky figure of 94.1mpg from a hybrid, you're likely to wonder what has happened to your extra 30mpg...
Nissan Juke 1.2 DIG-T - 33.5mpg = 68%
A lot of people buying a Nissan Juke will use it for short journeys and around town - so a petrol engine makes perfect sense. But it's hard to recommend the 1.2 DIG-T here. It returns less than 35mpg - the worst economy in this list - and way short of the maximum 50mpg that's promised.
Lexus NX 300h - 37.8mpg = 68%
While Toyota performs strongly in Real MPG when it comes to hitting claimed economy, Lexus does less well. The RX 450 h doesn't feature due to the fact we have had less than 50 submissions in Real MPG, but we have more than 100 owners of the NX300h who are telling us that the hybrid SUV is falling significantly short of the claimed figures.
Ford Focus ST 2.0 TDCi - 46.6mpg = 69%
Hot hatches are seldom associated with outstanding fuel economy. That’s why a few carmakers, like Ford, have produced diesel versions. All the style and fewer of the huge fuel bills, right? Perhaps not. The Focus ST diesel struggles to get anywhere near its advertised 67.3mpg.