Economical execs: our top 16 most efficient cars rated

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15.) Volvo S60 2.0 D4 SE Lux Nav Manual

Official: 74.3mpg

True MPG: 48.3mpg

Enjoyable to drive, good value for money and with plenty of equipment as standard, not to mention the great safety credentials you expect from Volvo. The S60 is a departure from the norm, and the diesel emits only 99g/km of CO2 yet manages a sub-7.0-second 0-60mph sprint.

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14.) Audi A6 2.0 TDI Ultra S line auto

Official: 64.2mpg

True MPG: 49.8mpg

Audi A6 is a great all-rounder, with plenty of equipment in S line guise and a spacious, beautifully built interior. This refined, big saloon almost hits the magic 50mpg benchmark.

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13.) Mercedes CLA220

Official: 62.8mpg

True MPG: 50.0mpg

Saloon version of Mercedes A-Class offers a spacious load area and generous kit. The CLA220 isn’t the roomiest contender in the rear, but the diesel version can achieve 50mpg.

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12.) Audi A3 Saloon 2.0 TDI 150 S line auto

Official: 68.9mpg

True MPG: 51.2mpg

The first and more powerful of two Audi A3s on our list, the 2.0 TDI is a solid performer yet kicks out only 105g/km. Impressive.

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11.) Lexus GS300h

Official: 60.1mpg

True: MPG 51.4mpg

Lexus GS300h offers the great economy and CO2 emissions you’d expect of a hybrid model, plus excellent build quality, refinement and reliability. Load space is a little compromised by the battery pack, however, and neither is the cabin as large as you’d expect.

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10.) Volkswagen Passat 2.0 TDI Bluemotion

Official: 68.9mpg

True MPG: 52.5mpg

Latest version of this ‘old-timer’ really ups its game compared with both its predecessor and its rivals. The VW Passat is spacious, well built and comfortable inside, and makes a satisfying and user-friendly cruiser that returns fine economy.

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9.) Audi A3 Saloon 1.6 TDI auto

Official: 72.4mpg

True MPG: 52.7mpg

The second Audi A3 on our list offers 52.7mpg – although the 20mpg differential to its claimed economy isn’t so impressive… Still, it’s a treat to drive, with among the most refined, well designed and highest-quality cabins on our list. The standard-fit sports suspension detracts from the ride, however.

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8.) BMW 520d SE

Official: 62.8mpg

True MPG: 54.5mpg

This BMW 5 Series turbodiesel performed better in the real world relative to its official figure than its rivals here, almost matching some of the higher-placed hybrids in our comparison. Impressive quality, refinement and performance – and £10k less to buy than the Mercedes E300 Hybrid placed one position ahead of it.

7.) Mercedes E300 Hybrid

Official: 65.7

True MPG: 54.6mpg

Superb fuel consumption and CO2 emissions of a mere 109g/km make this Mercedes E300 Hybrid the most efficient car in its class and a great company purchase – although its expensive asking price isn’t private-buyer friendly. Recently facelifted, but the 5 Series has the edge for cabin quality and dynamics.

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6.) Mazda 6 2.2 Skactiv-D

Official: 64.2mpg

True MPG: 54.8mpg

The maths make sense on this efficient and powerful Mazda 6 turbodiesel, thanks to low CO2 emissions and impressive economy. Long, fast cruises can be less relaxing than some thanks to the firm handling and ride.

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5.) Mercedes C200 Bluetec AMG Line

Official: 72.4mpg

True MPG: 55.0mpg

The first of two C-Classes to make our top five. You have to work the Merc’s 1.6-litre turbodiesel hard to get the best performance, and it certainly makes itself heard, but the smooth ride aided by optional Airmatic suspension is sublime.

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4.) Audi A4 2.0 TDIe

Official: 65.7mpg

True MPG: 55.5mpg

A sensible financial move, this evergreen Audi has a competitive list price and good residuals. The A4 boasts fine handling and a good engine line-up elsewhere in the range, although the ride is a little firm and the dash layout lags behind some competitors’.

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3.) BMW 320d Efficient Dynamics

Official: 68.9mpg

True MPG: 56.0mpg

A top-three finish for the frugal BMW 3 Series, which has CO2 emissions of 109g/km. Spec the optional adjustable suspension for optimum handling prowess.

2.) Mercedes C300 Hybrid

Official: 78.5mpg

True MPG: 57.8mpg

One of two hybrids in our top three, and nearly 58mpg in a model of the C300’s size is to be applauded – even if the shortfall between real-world and official economy earns Mercedes a black mark. A fabulous interior further enhances the credentials of this mid-size exec saloon.

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1.) Lexus IS 300h

Official: 64.2mpg

True MPG: 59.6mpg

Our winner – in both the hybrid chart and overall. Excellent build quality, reliability and low CO2 figures all go towards making the Lexus IS 300h a perfect company car and cheaper than diesels. Only a drivetrain drone detracts from the refined experience, while ride is better on lesser-spec models.

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