The best diesel engine cleaners

Written by Ryan Gilmore Published: 22 December 2022 Updated: 6 December 2023

Diesel engine cleaners are still a mainstay of the car care routine of diesel owners despite diesel cars being in decline across the UK, but they still remain a solid choice if you’re regularly doing long journeys. Not much can come close to diesel in terms of motorway fuel efficiency, and there are still plenty of diesel vehicles available, both new and used.

One issue that plagues diesel, however, is the build-up of carbon deposits over time. It’s a perfectly natural occurrence and shouldn’t do lasting damage, but affects your engine’s efficiency. Diesel cars lose power, emit more harmful emissions and use more fuel if these deposits go unchecked. A number of engine components are affected; injectors, turbos and emissions equipment can all suffer at the hands of carbon deposits.

Thankfully, there’s a simple solution. A diesel engine cleaner will remove these deposits and allow you to enjoy the full potency of your diesel car. The best part is that the majority of them are fuel additives, meaning you just bung it in your fuel tank (with regular diesel) and simply drive around as normal to clean your engine out. Join Parkers as we guide you through the best diesel engine cleaners currently for sale.

The best diesel engine cleaner

When should I use a diesel engine cleaner?

Diesel engine cleaners, also known as diesel fuel additives or injector cleaners, can be used to improve the performance and efficiency of diesel engines and to help them last longer. Periodically adding a diesel engine cleaner to your fuel tank should be part of your routine maintenance and can help prevent carbon build up in the injectors and keep the engine running smoothly.

Other times to use a diesel engine cleaner include:

Fuel System Issues: If you’re experiencing symptoms like rough idling, poor fuel efficiency, excessive smoke, or reduced power, it may indicate issues with the fuel system, such as clogged injectors or a dirty fuel filter. In such cases, a diesel engine cleaner can help clean the injectors.

Cold Weather: In cold climates, diesel fuel can gel and cause problems in the fuel system. Some diesel additives include anti-gel properties to prevent fuel from gelling at low temperatures.

Biofuel Blends: If you’re using biodiesel or other biofuel blends, a diesel engine cleaner can help mitigate issues related to water and microbial growth in the fuel system.

Emissions Testing: A diesel engine cleaner can help reduce harmful emissions and improve the chances of passing MOT emission tests.

Fuel Economy: If you’re looking to improve fuel efficiency, some additives claim to enhance combustion and increase miles per gallon (MPG).

Older Engines: Older diesel engines may benefit from engine cleaners to remove carbon deposits and improve overall performance.

When using a diesel engine cleaner, it’s important to follow the manufacturer’s recommendations for the specific product you choose. Different products have different formulations and purposes, so be sure to read the instructions and dosage recommendations on the product label. Additionally, be aware that not all engine cleaners are created equal, so it’s important to choose a reputable product from a trusted manufacturer.

Keep in mind that regular maintenance, including changing fuel filters and using high-quality fuel, is also crucial for keeping your diesel engine running smoothly.

Ryan Gilmore is the Deputy Autos and Tools Editor for Parkers, specialising in car cleaning and hand tools. A veteran car cleaner; if it details, waxes or washes he’ll be on hand to make sure it’s worth your money.

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