The best diesel engine cleaner 2025

If you're looking for the most comprehensive engine cleaner that represents great value for money and cleans up as many parts of a diesel engine as possible, STP's 5-in-1 fuel system cleaner is hard to match. Not only does it dissolve carbon deposits, but but it's safe to use in all diesel engines and tackles things from the injectors to the fuel lines and EGR valves.

Being a diesel engine's equivalent of a juice-cleanse, the STP 5-in-1 cleaner will flush out deposits, restoring lost power and boosting overall fuel economy. It also works as a preventative measure against further deposits building up.

One of the best value options out there is the Diesel System Cleaner by Redex. In 500ml of product you get four shots of diesel cleaner and it's an ideal product for regular engine maintenance, with the only expense being you inserting it with every time you fill up.

It helps remove carbon deposits that build up on your fuel injectors, and if they were badly clogged before, you'll restore a bit of performance and efficiency to your engine. Redex also produce a petrol system variant of this product too, which also massively helps with engine smoothness and cleanliness.

If your turbocharged diesel engine is missing some boost, then it may be partially blocked from deposit build-ups due to high miles without cleaning. Turbos need to be running efficiently to get the most our of your engine's performance and efficiency, and this product by Wynn's is designed to do just that.

Wynn's Diesel Turbo Cleaner is designed to clear these turbochargers and restore lost performance to your engine. Obviously, make sure your car is a turbo diesel before purchasing as it won't be effective on N/A units.

A diesel particulate filter (DPF) will reduce soot emissions and make a diesel engine cleaner. However, DPFs can get clogged with soot easily, reducing engine power and decreasing fuel efficiency.

This particulate cleaner from Wynn's will remove these soot emissions, making your engine run smoother and cleaner. It targets DPF filters as these can get commonly clogged up with soot and carbon build-ups. It's designed for regular diesel cars and also diesel hybrid vehicles. It's particularly beneficial to diesel vehicles that regularly do urban driving, which in most cases, is where soot is most likely to build up in the filters and other components.

As cars get older, they inevitably start to run less efficiently due to carbon soot and build-up in various parts of the engine. The injectors can be one of them, and an engine can run quite roughly if they're not cleaned in a higher mileage engine.

This highly concentrated additive from STP is specially formulated for cars with higher miles on the clock to remove stubborn deposits and boost engine power. It will also help protect your engine too and give it the cleanliness it deserves.

The EGR (Exhaust Gas Recirculation) system reduces harmful Nitrogen Oxide emissions (N2O) and is important for modern diesel engines. The EGR valve is central to reducing these emissions but can become clogged by particulate build-up. This can lead to running issues which can be noticeable if affected.

This product from Wynn's is not a fuel additive but an aerosol that cleans the EGR valve, air intake system and inlet valves. It isn't as simple as inserting the product into the fuel tank, and you have to be prepared and very careful when spraying it towards the EGR valves.

Perfect for reducing emissions, Cataclean is designed to clean and protect your car's catalytic converter, DPF filters (diesel particulate filter), and so much more besides. This is the most comprehensive and thorough diesel engine cleaner on our list, and for really badly affected cars, it's worth having a go with it.

Not only is it capable of reducing overall diesel emissions, but will help restore performance and increase your overall fuel economy as well. The instructions are quite precise however. Cataclean recommends you add 500ml of the product for every 15-litres of diesel every three months. This makes it less straight forward to use than the others, but it promises some noticeable results.

Designed specifically with DPF filters and catalytic converters in mind, Nitrox's diesel cleaner is designed to be used every three months as part of your vehicle maintenance schedule and helps prevent carbon build-up and clogging, which leads to the failure of many components in a diesel engine.

You simply pour the product into the fuel tank and let it do its thing, just like most others. If your car is clogged with soot and carbon build-up, it can help clear them and subsequently improve your emissions readings.

Diesel particulate filters can get clogged up if they're not cleaned, and this can lead to running issues in later life of diesel engines. For two 250ml bottles, Liqui Moly's DPF cleaners are roughly the same price as one 5-in-1 engine cleaner.

It's designed to cater for cars which are used for short trips and within urban traffic, as these are more likely to build up soot than motorway-driven vehicles. To use, you simply insert it into the fuel tank every 2,000km (1,240 miles). One single can is sufficient for every 50 to 70-litres of diesel.