What Car?'s latest True MPG tests reveal the fuel economy buyers can really expect from several family cars. Unlike official tests which measure fuel usage in a laboratory, What Car?'s True MPG tests use special equipment to measure exactly how much fuel a car consumes on a real-life test route.
More models are subject to What Car?'s True MPG tests every day, and the latest include some popular family cars, large and small.
The Mazda CX-5 2.0 Skyactive-G 2WD returned an impressive average economy of 41.3mpg. That's 5.7mpg down on its official figure of 47.0mpg but only 5.9mpg less than the 2.2 Skyactiv-D 2WD diesel model, which achieved 13.2mpg less than its official figure.
Another compact SUV just tested is the Kia Sportage. The 2.0 CRDi 134 auto came exceptionally close to matching its 40.0mpg official figure, with a real-world average of 39.1mpg.
Large diesel engines tend to perform well in True MPG tests but the Audi A6 Avant 3.0 TDI 204 Multitronic bucked this trend. Although its True MPG average of 42.7mpg is respectable enough, it's some way from the car's official figure of 54.0mpg.
The BMW 520d Touring auto is another executive estate that's recently been tested. It averaged 48.2mpg – an impressive figure for such a large car though not quite a match for the 55.0mpg official figure.
A large, diesel-engined car that performed even better was the Skoda Superb 1.6 TDI CR. Its True MPG average of 53.1mpg is just 2.9mpg short of the official figure and makes it one of the most fuel-efficient cars in its class.
The Ford Focus 1.0 Ecoboost offers the performance of a petrol with the fuel economy of a diesel, if its official average economy is anything to go by. However, our testers found this Focus model fell some way short of its official figure of 56.5mpg, with a True MPG result of just 38.2mpg.
On paper, the most economical Volvo V40 is the 1.6-litre diesel D2, with an official average of 78.5mpg. However, our True MPG testers found it returned a less impressive 56.8mpg.
Most MPVs are bought with diesel engines, but Renault offers a 1.2 TCe petrol in its Scenic, which has an official mpg of 48.0. Our True MPG tests revealed that it wasn't as impressive in real-world driving, with an average of 36.6mpg.
Parents looking for a first car for their teenager may be considering the Fiat Panda. The 1.2-litre petrol model is one of the cheapest city cars on the market and its official average economy of 54.3mpg means it also promises to be cheap to run. However, Our True MPG tests revealed a rather lower figure of 43.1mpg.
Visit the True MPG website and you can find the True MPG figure for your car, tailored to how and where you tend to drive. There's also information on how the tests are conducted and advice on how to save on fuel.