Finding the best diesel engine cleaner remains essential for diesel car owners concerned about car care across the UK, despite declining sales. Nothing matches diesel’s motorway fuel efficiency, and plenty of vehicles are still available 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 does 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 contribute to issues caused by carbon deposits. There are a number of ways to solve this, including the ever-so-popular diesel injector cleaners. But there are also far more comprehensive products than those out there, so if you want a total clear-out of your engine then engine flush is the way to go.
Best diesel engine cleaners at a glance
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 can put it in your fuel tank (with regular diesel) and simply drive around as normal to clean your engine out. If you don’t own a diesel vehicle, then don’t worry – petrol engine cleaners are available too.
How to choose the best diesel engine cleaner
Key factors to consider
Compatibility – It is important to find a diesel engine cleaner that is compatible with your engine. Some cleaners will only target certain components of the engine whereas others will be a general cleaner. It goes without saying: always look for a diesel engine cleaner for a diesel engine.
Type – As mentioned above, if you’re looking for a specialised cleaner then there are plenty of products on the market. If you’re looking for something that’s a little more comprehensive then a complete system cleaner might be better.
Concentration and dosage size – We always recommend reading the product instructions as they will differ from one product to another. Be sure to use the correct amount of product as you won’t see a difference when using less cleaner, and too much cleaner may do more harm than good.
Price – Getting the best value can be confusing with varying product sizes. Look for lower-priced options that clean and protect your engine longer. Since performance varies between products, research thoroughly or check our recommendations below.
Types of diesel engine cleaners
Fuel system cleaners – For a comprehensive clean a fuel system cleaner that gets rid off deposits in the fuel injectors, intake valves, combustion chamber, and fuel lines will be the best option. Benefits of fuel system cleaners include: improved fuel economy, better performance, and reduced emissions.
Injector cleaners – Fuel injectors clear carbon deposits in the injectors to improve fuel spray, which helps improve fuel economy and performance, as well as reducing blockage. If your car suffers from a rough idle or an engine misfire then an injector cleaner might be for you.
Turbo and EGR valve cleaners – Just like injector cleaners, turbo and EGR valve cleaners focus on a particular component of the engine. Turbo cleaners will clear the vanes of carbon deposits in the turbocharger allowing it to work more efficiently with less turbo lag and increased power. Exhaust Gas Recirculation (EGR) system cleaners will do the same for the EGR valve.
The best diesel engine cleaner
Editor's choice
Pros
- Reduces emissions for clean engine running
- Improves fuel economy and smoothness for your engine
Cons
- Difficult to notice improvements in performance
Best multi-purpose cleaner
Pros
- Great for removing deposits and cleaning engine
- Improves engine performance for more efficient power delivery
Cons
- Might not be as effecting in improving fuel economy
Best diesel turbo cleaner
Pros
- Helps restore performance and engine power
- Protects turbochargers and saves from expensive repairs
Cons
- Only useful for turbo diesel engines
Best diesel cleaner for injectors
Pros
- Formulated to help with cold conditions
- Improved power delivery for better engine performance
Cons
- Only useful for cleaning fuel injectors
Best diesel engine cleaner for EGR systems
Pros
- Reduces harmful emissions for cleaner driving
- Protects EGR to avoid hefty repair bills
Cons
- Will not help engine performance
Best particulate filter cleaner
Pros
- Reduces soot emissions that harm the environment
- Avoid maintenance costs by cleaning the DPF
Cons
- Doesn't target other areas of the engine
Best value diesel engine cleaner
Because Redex insist you apply it to every tank, it's best used continuously for notable effects.
Pros
- Great value
- Very effective engine and injector cleaner
Cons
- Has to be used continuously to have effect
Best for high mileage diesel engines
Pros
- Perfect for cars with over 75,000 miles on the odometer
- General engine care and maintenance
Cons
- Lower mileage cars will see minimal results
Best all-rounder
Pros
- Works in lower temperatures
- Increases lubricity to avoid excess friction
Cons
- Dosage may be a little tricky to work out
Best for longevity
Pros
- Great all-rounder for peace of mind
- Can be used in double-dose for extra strength
Cons
- Instructed to use at every fuel stop
How to use diesel engine cleaners safely and effectively?
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 equally, so choose a reputable product from a trusted manufacturer. Different diesel engine cleaners require you to use them at different intervals: for example the Redex diesel system cleaner requires you to use a shot in every tank of fuel, whereas the Cataclean cleaner is to be used in 15 litres of fuel in every three months.
Diesel engine cleaners are typically inserted into the fuel tank in the same way that you would fuel your car. Some cleaners will suggest inserting the cleaner before fuelling, while others might recommend inserting after fuelling. Be sure to avoid overfilling with diesel engine cleaner. You might not see results right away, but with regular use you’ll start to find your car running smoother with better fuel economy.
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 these components.
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 that built up overtime and improve overall performance.
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.
Can diesel engine cleaner damage my engine?
Yes, if you use too much. It is important to always follow the manufacturers instruction as each cleaner is unique and improper use can do more harm than help. Too much engine cleaner, or a poor quality cleaner, can damage components like seals and gaskets. It is always crucial that you check if the cleaner you’re using is compatible with your vehicle, as you want to avoid a nasty bill when damage is caused.
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