WhatCar? magazine’s latest figures show which cars are getting drivers the most miles out of a gallon of fuel.
All of the top ten are diesel models, but none of them live up to the manufacturer’s official miles-per-gallon (mpg) figures. This is not down to dishonesty on their part, says WhatCar? but it’s the result of being forced, under EU regulations, to test cars in laboratory conditions rather than taking them out on the road.
How cars are tested
In an attempt to provide more realistic mpg figures, the WhatCar? 'true mpg' test puts cars into real-world conditions, starting with an urban route with an average speed of 15mph, followed by a spin on dual carriageways and motorways at an average of 60mph, before finishing with another loop around the urban circuit.
Engines are brought up to temperature prior to the test and the cars are driven at a steady pace to keep efficiency as high as possible to get the most out of the cars. Sensors capture data about each run, such as CO2 emissions, road speed and exhaust manifold pressure, which is all factored in when determining the True MPG of the vehicle.
The most economical cars that were put through their paces over the past twelve months all have diesel engines and most have a 1.6l engine size. All prices given are for new vehicles.
You can of course save a huge amount by buying second hand, but the mileage vs price reduction trade-off needs to be carefully considered on the facts of each individual case.
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1. Seat Leon 5DR SE Ecomotive 1.6 TDI 110
Official mpg: 85.6
True mpg: 63.2
This family five door did extremely well in the test, managing a very decent real-world average of 63.2 miles to the gallon. Although it gave the best performance, it still does 26% fewer miles than the official figures suggest, making it a particularly good example of why the figure cited by retailers should be taken with a pinch of salt.
On the road from: £19,925
2. Citroën DS3 e-HDi Airdream DSport Plus
Official mpg: 74.4
True mpg: 63
Coming in just below the Leon SE, the DS3 supermini does 63 miles to the gallon on a 1.6l engine. It is a three-door hatchback with a stylish design and good interior features, but the rear seat doesn’t have a lot of room.
On the road from: £17,250
3. Mini Cooper D
Official mpg: 80.7
True mpg: 62.6
The Mini Cooper D is also not far off the top spot with a True MPG of 62.6. It has a slightly smaller engine than the cars above, but seems to have found favour on the whole, with positive reviews from Auto Car and Auto Express, the first noting that it runs “like a much larger car”.
On the road from: £16,635
4. Skoda Octavia Greenline III TDi CR 5dr
Official mpg: 88.3
True mpg: 61.9
This five-door variant of the Octavia model did better than the estate version of the car which is further down this list. That said, its real world estimate slashed more than 26 miles off the distance you can expect to travel on a gallon of fuel, although the new figure isn’t too shabby. It has plenty of storage room and offers good value for the price.
On the road from: £21,320
5. Honda Civic i-DTEC EX+
Official mpg: 72.4
True mpg: 61.8
Though it did well judged on its efficiency, the Civic EX+ came under fire for a noisy engine and a restrictive driving experience. The are “far too many ergonomic issues,” says WhatCar?, and the headroom is not great. So while the engine performance is good (for both the petrol and diesel variants), you might run into issues to do with practicality and comfort while driving.
On the road from: £25,140
6. Seat Leon ST SE Ecomotive 1.6 TDi 110
Official mpg: 85.6
True mpg: 61.5
A close cousin to the five door in first place, the estate model doesn’t quite live up to same standard by about a mile and a half. The refinement isn’t perfect, according to reviews, but it’s got enough bells and whistles to keep you interested in the cabin, while the ride is stable.
On the road from: £20,920
7. Peugeot 308 Allure BlueHDi
Official mpg: 88.3
True mpg: 60.8
[SPOTLIGHT]The test slashed nearly thirty miles off the expected fuel efficiency this car delivers, but it has low emissions and an engine that goes the distance on low revs.
On the road from: £14,995
8. Citroën C4 Cactus Flair BlueHDi
Official mpg: 83.1
True mpg: 60.1
This car has a rather unusual design, but if you can live with that and the ‘Airbump’ panels on the side of the car that claim to protect from bumps and scrapes , it does a fair amount of miles to the gallon.
On the road from: £12,990
9. Skoda Octavia Greenline III TDi CR Estate
Official mpg: 88.3
True mpg: 59.4
We’re now into sub-60mpg territory. The estate version of the Skoda Octavia is supposed to be just as efficient as the hatchback, but it’s not. The optimistic 88.3mpg is cut by nearly a third in reality, so it’s doing two and a half miles less to the gallon than the hatchback.
On the road from: £21,170
10. Hyundai i20 SE CRDi
Official mpg: 68.9
True mpg: 59.4
The lowest of the top ten, Hyundai’s i20 SE CRDi still manages a decent 59.4 true mpg rating, and is the car with the lowest overestimated official mileage, though it’s still a significant 13.8%. It has the smallest engine in the list, a 1.4l.
On the road from: £14,725
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Cars that didn’t do so well
The least efficient car tested by WhatCar? in the last twelve months was Vauxhall’s VXR8 which did a measly 19.5mpg – but even that exceeded its official figure of 18.5mpg.
Meanwhile, the Ford Fiesta Zetec S came out of the test with the biggest gap between its supposed mpg and real-world equivalent. It should manage 62.8mpg, according to the official numbers, but did just 39.7mpg when tested out. That’s a whopping 36.8% difference.
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