What are the cheapest used cars to run?

Used cars with low running costs

Economical used cars to buy

When you’re buying a used car, the price you pay on the forecourt is just the beginning. There’s also fuel, road tax, insurance and more to think about, so how do you know which cars are going to keep costs low?

Petrol vs. diesel

Fuel economy is a very important concern when buying a used car, and choosing whether to buy a petrol or diesel is also one of the most fundamental decisions you’ll make.

Diesel cars tend to burn slightly less fuel, but petrol is (usually) cheaper at the pumps and petrol cars are often cheaper to buy in the first place. Older diesels can also take a while to warm up, too, making them more polluting and less efficient on shorter trips around town. So unless you’re going to be doing lots of miles and regular long journeys, it may be worthwhile sticking to petrol.

Engine size

There used to be a pretty linear correlation between power and fuel efficiency. The rules said: the bigger the engine, the more powerful it is, the more fuel it uses. That’s not always the case these days, however, so it pays to inspect used car listings with care.

There are two reasons for this. Firstly, some of the more powerful cars on sale these days use turbo charging to boost power from smaller engines. Smaller engines are more efficient, creating a paradox where sometimes the most powerful (and expensive) engines are the cheapest to run. That means that cars with bigger, naturally-aspirated engines can be cheaper to buy up-front, but cost more in fuel and road tax.

The second reason is even more confusing. Rather than engineer several different engines to offer customers choice, these days manufacturers like Ford will sometimes create a single engine (like the efficient 1.0-litre EcoBoost in the latest Focus) and use computer software to offer different versions of it. This often doesn’t have any impact on economy or emissions, so you might not save money by opting for a less powerful version.


The gearbox is another area that impacts running costs. Manual cars tend to be cheaper to buy, but they promote a more racy driving style that pushes up fuel consumption – and there’s always the future cost of a replacement clutch to think about.

Automatic cars are rarer and more expensive to buy both new and used, but they tend to be more relaxed in style and may be more fuel efficient because they are always in the ‘right’ gear. You might recoup the extra outlay over time if you do lots of driving.

Road tax

For any car registered after March 2001, the price of road tax is linked to how much CO2 comes out of the exhaust. This can really have an impact if you’re looking at older cars registered after this date. Figures are given in grams per kilometre (g/km) and the more polluting the engine is, the more expensive it is to tax – it can be up to £515 a year (based on 2016 prices).

You’ll find an indication of the annual road tax cost on every used car listing on PeoplesCars.co.uk.


Insurance is an unavoidable cost, so save where you can. Put simply, the smaller and less powerful the car, the cheaper it is to cover. The bad news is that there’s not much correlation between the value of the car and the cost of cover.

You’d think older cars would be cheaper because they’re worth less, but it can be harder to source parts for repairs and they can be more susceptible to theft. What’s more, they may not provide the same protection for occupants in the event of an accident. Make sure you get lots of quotes and find the best balance between cover and price.


Spending a little money on a regular service could help you save a lot in the long run. Comprehensive servicing helps the car to retain more value when it comes time to sell it on, and makes it run more efficiently too. Catastrophic failures can also be averted by sticking to the manufacturer’s recommended maintenance schedule. Replacing the cam-belt when it is due will cost a fraction of rebuilding the engine should it snap, for instance.

Start the search

Now that you know what to look out for, it’s time to find your perfect used car. View our used cars for sale online or visit your nearest Peoples showroom now.