Most fuel-efficient cars to buy in 2019

Cut your trips to the petrol station with the most fuel-efficient cars on sale in 2019

BuyaCar team
Mar 19, 2019

If you're looking for the most fuel-efficient modern car, then you'll need a hybrid. More specifically, you'll need a plug-in hybrid car.

Apart from fully electric cars - which are increasingly affordable and appealing - plug-in hybrid vehicles can be the most efficient vehicles on the road today, depending on how you use them.

They have a conventional diesel or petrol engine, in addition to a battery pack that can be charged up. This allows most plug-in hybrid cars to drive for between 20 and 30 miles using mainly electric power and dramatically cutting fuel costs.

It's a different story when the battery runs out and the engine starts, though: on longer journeys, plug-in hybrids can still be efficient, but few are any better than a modern diesel car, which would normally be cheaper than a plug-in hybrid.

That's why you shouldn't rely on official fuel economy figures: they vary wildly depending on how the car is driven. The higher cost of plug-in cars means that they can be more expensive to run, despite the fuel savings - unless you're a business user. The low carbon dioxide (CO2) emissions recorded in official tests cut the cost of company car tax, at least until the rules change next year to favour electric cars.

We've listed the ten most efficient cars on sale today - each one a plug-in hybrid car. If you're unsure if this is the right technology for you, click below on our guides to other efficient cars. 


Most fuel-efficient cars 2019


1. Hyundai Ioniq PHEV

Best economical car for efficiency on all journeys

Latest Hyundai Ioniq PHEV deals from £20,990
Finance from £317 per month 
Hyundai Ioniq PHEV 247.8mpg / 26g/km CO2


2. Toyota Prius Plug-in

Best economical car for futuristic design

Latest Toyota Prius Plug-in deals from £21,489
Finance from £268 per month 
Toyota Prius Plug-in 235mpg / 28g/km CO2


3. Kia Niro PHEV

Best economical car for a high driving position

Kia Niro PHEV 201.8mpg / 31g/km CO2

Kia Niro buying guide


4. Mercedes E-Class

Best economical car for diesel and petrol options

Latest Mercedes E-Class diesel deals from £13,499
Finance from £211 per month  
Mercedes E 300 de 201.8 / 41g/km CO2

Mercedes E-Class buying guide


5. Kia Optima PHEV 2.0 GDi

Best economical car for efficiency with a long warranty

Kia Optima PHEV
188.3 / 34g/km CO2

Kia Optima Sportswagon buying guide


6. Mitsubishi Outlander PHEV

Best economical car for SUV practicality without the price premium

Latest Mitsubishi Outlander PHEV deals from £12,999
Finance from £207 per month
Mitsubishi Outlander PHEV
139.7mpg / 40g/km CO2

Mitsubishi Outlander PHEV buying guide


7. BMW 5 Series

Best economical car for dapper looks and driving fun

Latest BMW 530e deals from £25,000
Finance from £328 per month 
BMW 530e
128.4mpg / 49g/km CO2

BMW 5 Series buying guide


8. BMW i8

Best economical car for speed

Latest BMW i8 deals from £48,303
Finance from £649 per month 
BMW i8
128.4mpg / 42g/km CO2

BMW i8 buying guide


9. Mercedes S-Class

Best economical car for the 1%

Mercedes S 560e
128.4mpg / 57g/km CO2


10. Volvo S90 / V90

Best economical car for Scandi-chic

Volvo S90/V90 T8
117.7mpg / 49g/km CO2

Volvo V90 buying guide


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