The mpg figures published in sales brochures can tempt you into buying a particular car, but those results can be misleading. Fortunately, What Car?'s True MPG tests reveal what sort of fuel economy you can expect in the real world.
To ensure accuracy and repeatability, our tests are conducted under strictly controlled laboratory conditions but based on a real route that takes in urban, A-road and motorway driving.
Below, we take a look at the most efficient family cars we've tested so far.
The most fuel efficient family cars
Official combined mpg: 57.6 True mpg 46.1 % difference 20.0%
The latest Seat Leon has really impressed us with its low ownership costs, classy interior and tidy handling, and this 1.4 EcoTSI petrol engine is the one we recommend. It features cylinder deactivation to lower fuel consumption on the motorway, but has more than enough power to cope with overtaking when required.
Official combined mpg: 65.7 True mpg 46.5 % difference 29.3%
This is the first of two entries for the big-selling Vauxhall Astra on this list, and here it's equipped with a turbocharged 1.0-litre petrol engine with 104bhp. It's a strong and flexible performer, with low CO2 emissions making it appealing to company car buyers. We've found plenty to like about the latest Astra, including its low purchase price and good levels of equipment inside.
Official combined mpg: 70.6 True mpg 46.9 % difference 33.6%
The Ioniq is Hyundai's first dedicated hybrid car, and the first signs have been promising. We've praised its good driving style and quality interior, and even though its True mpg result is over 30% adrift from what Hyundai claims is acheivable, it's still a good choice if you're looking for a hybrid car.
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