Fuel economy and running costs are often key considerations when choosing a car, and if these are high on your list of priorities a small diesel car could be a great choice for you. Diesel cars, by their nature, are more fuel-efficient than an equivalent petrol car, and the smaller and lighter the car, the better MPG you’re likely to get from it.
Many car manufacturers no longer offer small new cars with a diesel engine, preferring instead to offer their compact models with hybrid, petrol or pure-electric power. But small cars with a diesel engine can still be a great choice, especially if you cover a lot of motorway miles, and there are a wide choice of models available, either new or used.
Here, you’ll find a guide to our top 10 small diesel cars. For each one we’ve listed its combined MPG, according to official figures – you might not quite match it in real-world driving but you can be sure each one will give you excellent MPG.
The Best Small Diesel Cars 2025
- Citroen C3 (2016-2024)
- Peugeot 208 (2019-)
- Citroen C3 Aircross (2017-)
- Vauxhall Crossland (2021-)
- Dacia Duster (2019-2024)
- Ford Focus (2018-)
- Peugeot 2008 (2019-)
- Vauxhall Mokka (2021-)
- Volkswagen T-Roc (2017-)
- BMW X1 (2022-)
Citroen C3 (2016-2024)
Average MPG: 70.6
Citroen was one of the last car companies to stop offering a diesel engine in a supermini, so diesel-powered C3s can be found on the used car market that are younger than equivalents from other manufacturers. The French firm’s 1.5-litre BlueHDI 100 engine does sterling work in the handsome C3. It has 99hp on hand to deliver lots of low- and mid-rev shove, while the five-speed manual gearbox is easy to use.
With official combined consumption of 70.6mpg, the C3 is one of the best small hatchback cars out there for fuel efficiency, and CO2 emissions come in as low as 113g/km. Its forgiving suspension also makes it one of the most comfortable superminis to drive – we’re not quite talking Mercedes-Benz E-Class levels here, but the ride really is remarkably smooth.
Citroen C3 Review
Peugeot 208 (2019-)
Average MPG: 72.2mpg
Anyone who thinks small diesel cars are a thing of the past need only drive the Peugeot 208 1.5 Blue HDi 100 to see that’s not the case. Its appeal may be largely confined to those who cover a lot of miles, but they will appreciate its combined economy of 72.2mpg, which means you can cover more than 650 miles on a single fill of the 41-litre fuel tank.
The Peugeot 208 is a supermini you will want to spend time in, because it’s comfortable and stylish. The iCockpit interior with the steering wheel set low down and the instruments viewed over the top takes a little getting used to, but it works just fine. It might not be as much fun to drive as a Ford Fiesta or Renault Clio, but the 208 rides and handles very well.
Peugeot 208 Review
Citroen C3 Aircross (2017-)
Average MPG: 67.2
Most Citroen C3 Aircross customers will opt for the fine 1.2-litre petrol engine, but don’t rule out the 109bhp 1.5-litre turbodiesel motor if you cover plenty of miles. It’s ULEZ-compliant and, with average fuel consumption of 67.2mpg and 123g/km CO2 emissions, it’s very frugal.
You’ll also find the C3 Aircross is one of the most stylish and comfortable small SUVs on the market. There’s a good touchscreen infotainment system and the higher-spec models come with a wealth of standard equipment, making it surprisingly luxurious for such a small car. Despite its compact exterior the C3 aircross is remarkably practical, too, with some MPV-style versatility and enough passenger and boot space to make it a viable family car.
Citroen C3 Aircross Review
Vauxhall Crossland (2021-)
Average MPG: 62.8
A bit like the Vauxhall Corsa, the Crossland is a mainstay of its class and it’s easy to understand why when you look at the sharp styling of this small SUV. The diesel version was only available for a short period of time, but it gives rivals such as the Nissan Juke and Seat Arona a run for their money , and the 1.5-litre turbodiesel version also comes with a combined fuel economy figure of 62.8mpg.
The engine’s 109bhp output gives you a strong kick of acceleration from low speeds, and the six-speed manual gearbox is smooth and light to use. Emissions come out at 120g/km at their lowest, although higher trim levels sneak up to as much as 126g/km.
Vauxhall Crossland Review
Dacia Duster (2019-2024)
Average MPG: 58.9
Dacia offered a single 1.5-litre turbodiesel engine for the previous-generation Duster, but you can choose the dCi 115 motor with front- or four-wheel drive. Go with the former and you’ll be able to aim for the official average of 58.9mpg, while the 4x4 version comes in at a still respectable 53.3mpg. That's good going for a car that can handle a surprising amount of rough road driving, as are CO2 emissions of 127g/km and 141g/km for the two- and four-wheel drive models, respectively.
While it might not be as up-to-the-minute as the all-new model, the 2019-2024 Duster still looks great and it’s outstanding value for money. It’s relaxing to drive, with the emphasis firmly on comfort rather, than trying to compete with sportier offerings such as the Ford Puma or Audi Q2. The driving experience on the motorway is just as straightforward thanks to decent refinement, but the Duster trails most rivals with its relative lack of standard safety kit.
Dacia Duster Review
Ford Focus (2018-)
Average MPG: 67.3mpg
The Ford Focus has long been the go-to mid-size hatchback if you want a car that’s fun to drive and offers a wide range of models to choose from. Opt for the 1.5 EcoBlue model and you’ll get a diesel-powered family car that gives you great fuel economy and can also put a smile on your face when you’re tackling a favourite country road.
Average fuel economy is 67mpg+ for manual models and there’s also an automatic option that gives you up to 61.4mpg, depending on trim. Prices are extremely competitive and all versions are well-equipped. Ford discontinued Focus diesel models in 2024 (and will stop building petrol versions in 2025) but there are lots of used examples out there, offering a good choice of trim and equipment packages. An honourable mention here to the smaller Ford Fiesta, too – it was discontinued before the Focus but also offers a cracking blend of driving fun and fuel economy with its 1.5-litre diesel engine.
Ford Focus Review
Peugeot 2008 (2019-)
Average MPG: 65.7mpg
As an advertisement for the small SUV class, it’s hard to find a better poster child than the Peugeot 2008. Good looks are backed up by fine details on the outside and inside, and it also has enough practicality to make it a sound family choice.
For those covering more miles than most, the 1.5-litre BlueHDi 100 turbodiesel engine is a sound bet. It gives petrol rivals such as the Kia Stonic, Skoda Kamiq and Renault Captur a hard time thanks to its 65.7mpg potential. A smooth ride is complemented by nimble handling and excellent refinement. The downside is that the diesel is now only available as a used car, but it’s nonetheless worth checking out.
Peugeot 2008 Review
Vauxhall Mokka (2021-)
Average MPG: 65.7
Vauxhall offers something for everyone with the Mokka, from petrol engine power to an electric model and this, the 1.5-litre Turbo D model with 109bhp. Thanks to 65.7mpg combined economy and CO2 emissions as low as 114g/km, the diesel-fuelled Mokka remains a sound bet for anyone racking up the miles, although it's another example of the diesel being confined to second-hand models.
The Mokka is crisply styled and features a decent amount of interior space for passengers and luggage. It also comes with lots of standard safety kit, which helps offset the slightly dull driving manners of this keenly-priced small SUV.
Vauxhall Mokka Review
Volkswagen T-Roc (2017-)
Average MPG: 60.1
Volkswagen has kept the faith with diesel engines in its T-Roc where other models in the firm’s line-up have moved to petrol, plug-in hybrid or electric vehicles, such as the Volkswagen Polo and Volkswagen Golf. Buyers have a choice of 113- or 148bhp 2.0 TDI turbodiesel engines. The former offers a best combined economy of 60.1mpg, while the latter ranges from 51.4-57.6mpg depending on whether you select a two- or four-wheel drive model.
Inside, the T-Roc has a cabin that’s almost as roomy as a Skoda Karoq’s and it’s good to drive, if not quite as sharp as a Ford Puma. Even so, the T-Roc is one of the best diesel cars in its class and the SE trim comes with loads of equipment.
Volkswagen T-Roc Review
BMW X1 (2022-)
Average MPG: 58.9
Small diesel cars with a premium badge are few and far between these days. However, BMW’s smallest SUV offers all of the usual traits that drivers love, including fine handling and a lovely interior, along with a punchy diesel engine. The 2.0-litre turbodiesel comes in front-wheel drive sDrive 18d or four-wheel drive xDrive23d forms, with 148bhp and 194bhp respectively.
Choose the lower output model and you’ll have access to a claimed 56.5mpg average fuel economy, while the 23d gives up to 58.9mpg due to its mild-hybrid technology.
CO2 emissions for the 23d diesel models come in as low as 125g/km, while the 18d comes in at 131g/km. Whichever you choose, the X1 is a fine rival to cars from Jaguar, Land Rover, and Mercedes-Benz.
BMW X1 Review