The most and least efficient cars have been revealed in a series of real-world fuel economy MPG tests.

The best performing vehicle tested by What Car? was the Toyota Yaris Cross 1.5 Hybrid, which recorded a fuel economy rate of 60.1mpg, using just 11.2p of petrol per mile.

It was followed by the Toyota Yaris 1.5 Hybrid and Suzuki Ignis 1.2 Dualjet Hybrid, which both managed 59.9mpg.

The worst-performing vehicle tested out of 371 models was the Audi S8 performance saloon, which achieved 21.7mpg, which equated to 31p per mile.

The Alfa Romeo Giulia Quadrifoglio and Lexus LC Cabriolet were the next least efficient cars, achieving 23.5mpg and 24.2mpg, respectively.

To ensure accuracy and repeatability, What Car?’s ‘Real MPG’ tests were conducted under strictly controlled laboratory conditions but were based on a real route that replicates the effects of urban, rural and motorway driving.

While regular hybrid cars are included in the results, plug-in hybrids are not, because the figures for the latter vary dramatically depending on the distance being travelled and the amount of charge there is at the start of a journey, it said.

“There’s often a sizeable disparity between real-world driving efficiency and the official Government figures that carmakers are obliged to publish,” explained What Car? editor Steve Huntingford.  

“As our figures show, by choosing carefully, it’s possible to save a lot of money in the long-term, particularly with fuel prices as high as they are today.”

In the popular family SUV market, the gap between the best and worst performers was more than 28.1mpg.

10 best MPG results 

Make and model	What Car? Real MPG	Annual fuel cost (5550 miles)
Toyota Yaris Cross 1.5 Hybrid	60.1mpg	£621.87
Toyota Yaris 1.5 Hybrid	59.9mpg	£623.95
Suzuki Ignis 1.2 Dualjet Hybrid	59.9mpg	£623.95
Skoda Octavia 2.0 TDI 115 (no longer on sale with this engine)	57.9mpg	£688.42
Suzuki Celerio 1.0 (no longer on sale)	57.8mpg	£646.61
Vauxhall Astra 1.6 CDTi 110 Ecoflex (no longer on sale)	56.3mpg	£707.99
Honda Jazz 1.5 i-MMD Hybrid	56.0mpg	£667.40
Seat Leon 1.6 TDI 110 Ecomotive (no longer on sale)	56.0mpg	£711.78
Volkswagen Up 1.0 S/S 60	56.0mpg	£667.40
Suzuki Baleno 1.0 (no longer on sale)	55.2mpg	£677.07

10 worst MPG results 

Make and model	What Car? Real MPG	Annual fuel cost (5550 miles)
Audi S8	21.7mpg	£1722.32
Alfa Romeo Giulia Quadrifoglio	23.5mpg	£1590.40
Lexus LC Cabriolet	24.2mpg	£1544.40
Audi SQ5 (no longer on sale with this engine)	24.6mpg	£1519.28
Mercedes-Benz S-Class Cabriolet S500 (no longer on sale)	25.2mpg	£1483.11
Mercedes-AMG GLC 43	25.3mpg	£1477.25
Porsche Macan Turbo Performance Pack	25.3mpg	£1477.25
Land Rover Discovery 3.0 SDV6	26.3mpg	£1515.57
Mercedes-Benz S-Class S500 (no longer on sale)	26.9mpg	£1389.38
Volvo XC40 T4	27.1mpg	£1379.13