With the British government pledging to ban sales of new petrol and diesel cars by 2030, many motorists are questioning if it’s worth purchasing a fossil fuel powered vehicle. The short answer is yes, for many motorists purchasing a second-hand diesel car is a smart and eco-friendly choice. While diesel engines do harbour a dirty reputation, in reality they’re often cleaner and more affordable than petrol. Of course, credentials depend on variables like the year, make and model of the car and how you plan to use it. 

Should I buy a second-hand diesel car? If you’re weighing up your options, this article is for you. Read on as we navigate the pros and cons of buying a second-hand diesel car and take a look at some key factors to consider.

Emissions and environmental footprint

Emissions are one of the biggest factors to consider when shopping for second-hand diesel cars. While models manufactured in the early 2000s or before will generally offer disappointing emissions, purchasing a second-hand diesel car that’s only a few years old leaves a much lighter environmental footprint.

In 2017, the European Union introduced strict new Euro 6d-TEMP emissions testing mandating that diesel engines be fitted with Selective Catalytic Reduction (SCR) systems to break down NOx. So, if you purchase a diesel car manufactured after 2017 it will run much cleaner than a pre-2017 model.

According to the RAC, the average diesel car manufactured in 2020 has average emissions of 165.5g CO2/km. While this isn’t a gold-standard level it’s nowhere near as high as the emissions you’ll release by driving an older diesel car. In comparison, new petrol cars emit an average of 149.0g CO2/km, while new hybrid electric (HEV) cars emit 125.6 g CO2/km and Plug-In Hybrid Electric (PHEV) emit just 43.4g CO2/km.

BMW manufactures some of the cleanest diesel cars on the market, with the 3 Series one of the most popular models. MINI is another great option, with low NOx emissions and excellent fuel efficiency. Toyota, a long-standing eco innovator, also manufactures some great low emission diesel cars loved by eco-conscious drivers across the UK. The diesel-powered Ford Fiesta is another top contender, with the 2021 model clocking in CO2 emissions of just 82g/km. If you can get your hands on a used 2021 model you won’t have to compromise on emissions at all. In fact, you’ll be driving one of the most eco-friendly cars on the road.

Should I buy a second-hand diesel car if I want to reduce my emissions? The short answer is yes, so long as you carefully consider emissions and choose the newest model you can afford.

Fuel efficiency

Diesel offers more energy per litre than traditional petrol, meaning diesel-powered cars tend to offer excellent fuel economy. As a general rule, diesel cars use between 15 and 20% less fuel than petrol-powered vehicles. For example, the 2020 Kia Ceed 1.6 CRDi boasts fuel economy of 72.4mpg, making it one of the most efficient diesel cars on the market. This doesn’t translate to higher emissions, with the model clocking just 102g CO2/km. The Citroen C4 Cactus 1.6 offers similar fuel economy of 70.6mpg, while the Vauxhall Corsa 1.3 CDTI increases slightly to 78.5mpg. On long journeys where speed is kept high and constant, fuel economy increases to 88mpg.

Petrol prices

Price differences between petrol and diesel may be a factor for some people when purchasing a second-hand car. Diesel tends to be slightly more expensive than petrol, though only by a few pence. That said, while you’ll likely pay more to fill up your diesel tank, the fuel economy savings cancel out the extra cost at the forecourt and make diesel cars cheaper in the long run. For example, driving a diesel-powered BMW 1 Series 116d SE for 10,000 miles might cost around £830. The same model featuring a petrol engine would cost around £1,120, making diesel cheaper overall.

Road tax

Road tax can add a significant amount to the cost of owning a car, so it’s worth factoring in when shopping for diesel-powered vehicles. Rates are calculated using CO2 emissions and the age of your car. If your diesel car was registered after April 2017 when the EU introduced Euro 6d-TEMP emissions testing, tax will likely be cheaper.

Torque and power

Diesel engines tend to offer more torque than petrol-powered counterparts, making them a great option for towing caravans and trailers. This makes second-hand diesel cars a popular choice with motorists looking for towing power. Diesel engines also offer faster acceleration which can make overtaking slightly easier.

Making your choice

Should I buy a second-hand diesel car? Ultimately, the choice is yours. Whether you choose to purchase a second-hand diesel vehicle, opt for a traditional petrol-powered car or upgrade to an EV or hybrid will depend on your own unique preferences and priorities.

Before making a decision it’s important to do your research and track down a model that works for you. Do you prioritise low emissions over power and torque? Maybe you want to drive the most fuel-efficient car possible or slash your road tax rates? Taking the time to research second-hand diesel car options is the best way to ensure you make the right decision.

When you’ve settled on a model, you can search on our own used car stock list to see what’s available or choose from any reputable dealer. My Car Credit is here to help you secure the best car finance deals in the UK. With access to one of the country’s largest lending panels, we have the experience and expertise to track down tailored car finance rates, coupled with help and support every step of the way. Using our car loan APR estimator, you can find out how much you can borrow and what it will cost in a matter of minutes. Get in touch today to find out more and get behind the wheel of your dream second-hand diesel car.   

Rates from 9.9% APR. Representative APR 12.4%

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Representative Example

Borrowing £7,500 at a representative APR of 12.4%, annual interest rate (fixed) 12.36%, 47 monthly payments of £196.44 followed by 1 payment of £206.44 (incl. estimated £10 option to purchase fee), a deposit of £0.00, total cost of credit is £1,939.12, total amount payable is £9,439.12.

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