Real-world MPG: large executive cars that beat 50mpg

  •  Large saloons that won’t cost a fortune to fuel
  •  Three full-size executive cars beat 50mpg in our test
  •  Results indicate real-world fuel economy
  • Audi A6 2.0 TDI: True MPG 56.1mpg

    Audi A6 2.0 TDI: True MPG 56.1mpg

  • Mercedes E300 Hybrid: True MPG 54.6mpg

    Mercedes E300 Hybrid: True MPG 54.6mpg

  • BMW 520d: True MPG 54.5mpg

    BMW 520d: True MPG 54.5mpg


What Car?’s technicians drive new cars every week to capture our True MPG fuel economy data. Unlike official Government figures generated by a laboratory test, the numbers we publish are gained from real-world conditions.

This week we’re looking at the most economical large executive cars that we’ve tested so far, including our 2014 Best executive car over £28,000, the BMW 520d. These three cars should be on the shortlist of anyone looking for a plush, roomy saloon with fuel efficiency as a top priority.

1. Audi A6 2.0 TDI – official 57.6mpg: True MPG 56.1mpg

The Audi A6 is an impressively well-rounded executive saloon, offering decent refinement as well as a spacious, plush and well-built interior. True, the A6 isn’t as good to drive as the Jaguar XF and the controls aren’t as intuitive as in a BMW 5 Series - but it’s an accomplished rival for both. This cheapest 2.0 TDI in SE trim is our pick of the range, offering top-notch quality and plenty of equipment.

2. Mercedes E300 Hybrid – official 65.7mpg: True MPG 54.6mpg

This E-Class’s CO2 emissions of 109g/km means it’s the cheapest in the class for company car buyers. Its lofty official fuel economy is backed up by decent real-world performance, too. It’s a shame that the diesel is so noisy though, and the cabin doesn’t feel as classy as the BMW 5 Series’. Still, if you’re tempted by the E300, stick with SE trim to get the most comfortable suspension.

3. BMW 520d – official 62.8mpg: True MPG 54.5mpg

The latest BMW 5 Series has been one of our favourite large executive cars since it was launched in 2010. If you're in the market for a full-size exec, then it should still be at the top of your list. The 520d SE is the best bet for most buyers, although we recommend the optional Variable Damper Control, which improves the ride, and eight-speed auto ‘box that delivers super-slick shifts.

We add new models to our True MPG database every week. Visit to see the full range of cars we’ve tested, and find out what you really can expect to achieve on UK roads.


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