True MPG: best executive and luxury cars 2018
What Car?'s True MPG tests show what you can really expect from a car. Here we reveal the most efficient executive and luxury cars we've tested so far...
Official fuel economy: 62.8mpg; True MPG: 42.1mpg; Shortfall: 32.9%
The latest 5 Series is a classy, refined saloon with surprisingly low running costs, especially if you pick the 520d, which achieves more than 40mpg in real-world driving. It’s so good that we voted it our overall Car of the Year 2017.
Watch our BMW 5 Series video review
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Official fuel economy: 72.4mpg; True MPG: 44.8mpg; Shortfall: 38.1%
The E-Class has a well-deserved reputation as an elegant, cosseting large cruiser with plenty of equipment and good driving manners. Add to that fuel economy of 44mpg for the 220 d version, and it makes the E-Class a tempting prospect.