A by-product of good fuel economy is low CO2 emissions, which helps reduce greenhouse gas emissions: the latest Euro 6 models also have low NOx emissions to cut inner-city pollution.
But which are the most economical cars on sale in the UK? Here’s the full rundown of the greenest cars you can buy – and every single one of them emits less than 100g/km CO2.
FYI: We’ve taken figures from the official European NEDC test, and we’ve included regular petrol, diesel and hybrid cars, but not plug-in hybrids as these models will only give maximum economy if the batteries are fully charged.
1: Peugeot 208 1.6 BlueHDi 75 S&S – 94.2mpg
Two models share the honour of being the UK’s most fuel-efficient car on sale. First up is the diesel-powered Peugeot 208 which, in latest facelifted 1.6 BlueHDi 75 S&S guise, averages a heady 94.2mpg, combined with sub-80g/km CO2 emissions.
2: Toyota Prius – 94.2mpg
If diesel power isn’t for you, the new Toyota Prius also averages 94.2mpg courtesy of its petrol-electric drivetrain – with the added benefit of zero-emissions EV running at slow speed. It’s roomier than the Peugeot too – and has ultra-low CO2 of just 70g/km.
- Volkswagen to buy back half a million dieselgate cars
- New EQUA ‘NCAP for NOx emissions’ test revealed
- Daimler asked to ‘review exhaust emissions certification’ by US authorities
3: Peugeot 308 1.6 BlueHDi 120 S&S – 91.1mpg
If you really want a Peugeot but really need more space, the larger 308 is very economical too: the 1.6 BlueHDi 120 S&S version averages 91.1mpg, making it three cars on sale in the UK to officially average more than 90mpg.
4: Ford Fiesta 1.5 TDCi 95 S&S Econetic – 88.3mpg
The Ford Fiesta is Britain’s best-selling car and it offers an ultra-economical Econetic version of the 1.5 TDCi diesel that averages a heady 88.3mpg.
5: Hyundai i20 1.1 CRDi 75 Blue – 88.3mpg
The latest Hyundai i20 is a well-regarded supermini and the roomy five-door averages 88.3mpg in three-cylinder 1.1 CRDi 75 Blue diesel guise.
6: Renault Clio 1.5 dCi 90 ECO – 88.3mpg
Renault can’t quite match French rival Peugeot for claimed fuel economy but the 1.5 dCi 90 ECO version of the Clio is still impressive at 88.3mpg.
7: Vauxhall Corsa 1.3 CDTi 95 S/S Ecoflex – 88.3mpg
Vauxhall’s long-running 1.3 CDTi diesel engine remains very fuel efficient with the stop-start-equipped 95hp Ecoflex version capable of 88.3mpg.
8: Citroen C4 1.6 BlueHDi 100 S&S – 85.6mpg
The Citroen C4 is a forgotten family five-door hatchback but that hasn’t stopped the firm making fuel efficient stars: the 1.6 BlueHDi version averages over 85mpg.
9: Kia Rio 1.1 CRDi 75 ISG – 85.6mpg
Kia can’t quite match brand partner Hyundai’s heady fuel economy with its 1.1-litre CRDi 75 Rio, but it’s still good at 85.6mpg.
10: Toyota Yaris Hybrid – 85.6mpg
If you want a fuel efficient supermini but really don’t want diesel, take the Toyota Yaris Hybrid: its 1.5-litre petrol-electric drivetrain returns a claimed 85.6mpg.
Not found a car here that’s quite right? Here we bring you 10 more of the UK’s most economical cars – and you’ll note, not a single one officially averages less than 83mpg…
11: Vauxhall Astra 1.6 CDTi 110 S/S Ecoflex – 85.6mpg
The new Vauxhall Astra is the 2016 European Car of the Year – and it’s a fuel-efficient car too, with a 1.6-litre CDTi 110 S/S Ecoflex version returning 85.6mpg.
12: Volvo V40 D2 – 84.1mpg
Volvo’s new 2.0-litre four-cylinder diesel engine is fuel efficient in all applications. The very greenest is the 120hp version in the V40, which averages 84.1mpg.
13: BMW 116d ED Plus – 83.1mpg
The pace of BMW’s EfficientDynamics models may have slipped down the rankings a little but the rear-wheel drive 116d ED Plus still impresses with 83.1mpg.
14: DS 3 1.6 BlueHDi 100 S&S – 83.1mpg
Posh MINI rival DS offers an ultra-economical version of the DS 3 which, in 1.6 BlueHDi 100 S&S form, averages 83.1mpg.
15: Fiat 500 1.3 95 MultiJet – 83.1mpg
Fiat’s stylish 500 is a regular UK best-seller. For those seeking ultimate fuel economy, the 1.3-litre MultiJet 95 version will average 83.1mpg.
16: Ford Focus 1.5 TDCi 105 Econetic – 83.1mpg
Another UK best-seller that averages 83.1mpg, the 1.5-litre TDCi 105 Econetic Focus offers great fuel economy to the masses.
17: Mazda 2 1.5 Skyactiv-D – 83.1mpg
Can you resist the temptation to seek fuel economy in the fun-to-drive Mazda2 1.5 Skyactiv-D? 83.1mpg will be your reward if so.
18: MINI One D – 83.1mpg
The MINI Hatch is also brilliant fun to drive, meaning you’ll have to show masterful restrain to achieve the 83.1mpg claimed by the three-cylinder One D. We challenge you…
19: SEAT Toledo 1.4 TDI Ecomotive – 83.1mpg
SEAT’s understated Toledo is a very roomy budget-priced car. For ultimate money-saving ability, choose the Ecomotive version and 83.1mpg will be your reward.
20: Volkswagen Golf 1.6 TDI Bluemotion – 83.1mpg
The final car to average 83.1mpg is the Volkswagen Golf in economy-optimised 1.6-litre TDI Bluemotion guise. Forget dieselgate, this is a very fuel-efficient car in real-world use, full stop.