Real-world MPG: executive cars that beat 55mpg

  • Five executive cars beat 55mpg in our test
  • Most efficient saloon is Lexus IS300h hybrid
  • Results indicate real-world fuel economy
  • Lexus IS

    Lexus IS

  • Mercedes C-Class

    Mercedes C-Class

  • Audi A6

    Audi A6

  • BMW 3 Series

    BMW 3 Series

  • Audi A4

    Audi A4


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 executive saloons that we’ve tested so far, including the Lexus IS300h petrol-electric hybrid. These five cars should be on the shortlist of anyone looking for a smart saloon with fuel efficiency as a top priority, as all beat 55mpg in our test.

1. Lexus IS 300h – official 64.2mpg: True MPG 59.6mpg

The low CO2 emissions of the Lexus IS300h means that it’s cheaper to run than diesel rivals for business users. The lower spec IS models have the best ride, but it’s a shame that the petrol engine drones under revs through the CVT gearbox, because in other ways the hybrid is a rather refined car. Lexus’s reputation for excellent reliability and dealer service help make this a compelling company car option.

2. Mercedes C220 CDI – official 68.9mpg: True MPG 57.5mpg

The outgoing Mercedes C-Class is far from a class leader, but choose wisely from the engine and trim options and it could prove to be a powerful, comfortable, and well-equipped executive saloon. Safety and security are top-notch, and residuals are strong. The diesel engines sound awfully rough, but - as our True MPG test shows - they are at least very efficient.

3. 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. 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. Nevertheless, it’s an accomplished rival for both, and this cheapest 2.0 TDI is our pick of the range, offering top-notch quality and plenty of equipment.

4. BMW 320d Efficient Dynamics – official 68.9mpg: True MPG 56.0mpg

The BMW 3 Series’s Best executive car crown was snatched by the Audi A3 Saloon in our 2014 awards. The BMW still has plenty of appeal, though. This version has CO2 emissions of just 109g/km, and should prove incredibly frugal. It’s disappointing that you need to add the optional adjustable suspension to make it ride and handle as it should, but once you do, the driving experience is about as good as it gets.

5. Audi A4 2.0 TDIe – official 65.7mpg: True MPG 55.5mpg

The Audi A4 handles securely and has a wide range of powerful engines. However, like in its A6 sibling, the dashboard layout is far from the best in the business. The new A3 Saloon also shames its bigger brother as far as ride quality is concerned; the A4 is just too firm. However, thanks to reasonable list prices and strong residual values, the ownership costs are competitive.

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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