True MPG: most efficient diesel cars

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

25 April 2019
Nissan Qashqai, Volkswagen Touran, Audi A5, Vauxhall Insignia Grand Sport

The official government MPG figures published in sales brochures can tempt you into buying a particular car, but those results are often 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, we use strictly controlled laboratory conditions, but the tests are based on a real-world route that takes in town, rural and motorway driving.

The results reflect what's achievable if you’re driving gently and sticking to speed limits but aren’t resorting to any unrealistically slow acceleration or special 'hypermiling' techniques.

Here, we're counting down the 10 most efficient diesel-engined cars we've tested to date. Even though a lot of car buyers are choosing petrol or electrified cars over diesel power these days, the fuel is still a top choice if you regularly drive long distances on the motorway and want to keep your running costs low. 

Our top 10 includes family carscoupés, SUVs and even a people carrier. Read on to find out more about them. And if you're struggling to decide which fuel type is right for you, try our What Fuel tool.

10. Audi A5 2.0 TDI

Audi A5 2019 Front right cornering shot

True MPG 50.8mpg

The A5 is a seriously impressive executive coupé; in fact, it's our Coupé of the Year for 2019. This 2.0-litre diesel engine is a great choice too, thanks to its punchy performance and good fuel economy, netting you more than 50mpg in real-world conditions. Since our tests, this model's name has changed, though, so this is now the 40 TDI.

Read our full Audi A5 review, or see our latest A5 deals

9. Volkswagen Touran 1.6 TDI 115

New Renault Grand Scenic vs Citroen Grand C4 Picasso vs Volkswagen Touran

True MPG 50.9mpg

Want to move seven people but don't want an SUV? Enter the Volkswagen Touran. It's one of the best MPVs around, despite being one of the older cars in this market. We like the Touran's superb space and practicality, the fact that it's great to drive, and that you can buy one relatively cheaply thanks to impressive discounts and PCP finance deals.

Read our full Volkswagen Touran review, or see our latest Touran deals

8. Kia Sportage 1.7 CRDi

Kia Sportage

True MPG 51.4mpg

If you're looking for a less pricey family SUV, the Kia Sportage should definitely be on your list. You generally get a lot for your money – both in terms of space and equipment – and resale values are good too. This 114bhp diesel engine has since been replaced by a newer 1.6-litre variant with the same power output and should also prove to be an economical choice.

Read our full Kia Sportage review, or see our latest Sportage deals

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