Even with fuel prices dropping slightly at the start of 2015, the high cost of petrol and diesel is a major concern to millions. That's why so many new car buyers look straight for the most economical cars on the market.
A model with a high fuel economy figure will help save you money - and time spent filling up. To help you find the top models available now, we've listed the top petrol and diesel models for fuel efficiency.
It's not always best to buy one of these cars, however - this isn't our list of recommendations. A lot of the time you will save more money by going for a cheaper, less economical model. Plus, diesel cars are not fond of short journeys, so you'll likely face repair bills if you don't travel a lot of miles regularly - so it can be better to go for a petrol instead.
Official fuel economy figures, as quoted by the manufacturers, are notorious for being inaccurate in the real world. We think they are very useful, however. The official economy tests are standardised, so they don't include variations in driving style, traffic or weather - that means they are comparable, and a higher figure on the tests will likely mean a higher real-world figure, too.
We've decided to focus on non-hybrid and non-electric cars in our list here, as we've already put together round-ups for those models (see links, below). Instead, we’ve concentrated on conventionally-engined cars - especially as they are often much more affordable than their electrically-powered equivalents.
Electric cars do work for some people, though, so if you're looking for ultra-low emission vehicles, we've also got articles on the best hybrid cars, the best electric cars and even the best green cars on sale now.
Do remember that small diesel cars often boast excellent economy but this may not suit your lifestyle. Small city cars are great for commuting into town, but the tiny dimensions and cramped interior mean family trips can be very uncomfortable indeed - and there won't be much space for the shopping.
Diesel engines are not suitable for short trips, but work best for motorway travel - and small petrol engines are the opposite, working well in the city and getting noisy on faster roads. Also, diesel cars are usually more expensive than their petrol equivalents and are more costly to fill up. So if you don't cover long distances, a petrol car could make more financial sense.
You need to think carefully about which car will suit your needs best before you make a decision, rather than thinking purely about the fuel economy.
The cut-off point for our most economical cars list is an astonishing combined cycle return of 85.6mpg. Below that sit a cluster of fantastic cars that average over 80mpg but didn't quite make it into the fuel efficiency hall of fame. Any one of them should still be seriously cheap to run. Here's the best of the rest...
Citroen C3 1.4 e-HDi Airdream - 83.1mpg
Citroen C4 Cactus 1.6 BlueHDi - 83.1mpg
Ford Focus ECOnetic - 83.1mpg
Peugeot 208 1.4 e-HDi - 83.1mpg
Volvo V40 D2 - 83.1mpg
Skoda Fabia Greenline Estate 1.2 TDI - 83.1mpg