True MPG: most efficient executive and luxury cars 2019

What Car?'s True MPG tests show what fuel economy you can really expect from a car. Here, we reveal the best and worst-performing executive and luxury cars we've tested...

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What Car? team
15 February 2019

Audi A4 saloon front

4. Audi A4 2.0 TDI 190

True MPG 47.8mpg

A former What Car? Car of the Year, the A4 has since been beaten by the BMW 3 Series but remains a five-star car and will go slightly farther on a gallon of diesel.

Read our full Audi A4 review or see what discounts are available


3. Vauxhall Insignia Grand Sport 1.6 CDTi 110

New Vauxhall Insignia Grand Sport 2017 review

True MPG 50.2mpg

The bottom step on the podium goes to this 1.6-litre diesel model. Just bear in mind that you have to put up with quite a lot of road noise in all Insignia Grand Sports and rear head room is tight.

Read our full Vauxhall Insignia Grand Sport review or see what discounts are available


2. Vauxhall Insignia Grand Sport 1.6 CDTi 136

Used Vauxhall Insignia Grand Sport 2017-present

True MPG 51.8mpg

In official tests, the CDTi 136 version of the Insignia Grand Sport averages 2.8mpg less than the CDTi 110, but our True MPG figures show that the tables are turned in real-world conditions.