After plenty of research and testing, we found that the best fuel injector cleaner is the STP Ultra 5-in-1. It’s suitable for both petrol or diesel-powered cars and is designed to clean and protect the fuel system and injectors. However, if you would prefer a dedicated diesel fuel injector cleaner, the brand offers a diesel-specific alternative.
To rate the fuel injector cleaners, not only did we test several formulas (as shown in the image above), but we also based our recommendations on the latest research and a number of factors. Some of the factors that we considered included the additive’s cleaning abilities, brand reputability, treatment duration and value for the money.
Best Fuel Injector Cleaner Overview
- Best Overall: STP Ultra 5-in-1
- Best Budget: Redex Fuel System Cleaner
- Best All-Rounder: Wynns 55964
- Best For Diesels: STP Diesel
- Best Professional: Hydra Power Blast
- Best For Fast Results: Forte Diesel Specialist
For the best results when using a fuel injector cleaner, it’s advised that you pour the formula into the tank before you fill it up with fuel. The reason for this is that it allows the fuel and the additive to mix more efficiently rather than the formula just sitting on top of the fuel (if it was to be poured in afterwards).
Below is a list of the best fuel injector cleaners that restore performance, reduce fuel economy and easily mix with a full tank of fuel.
The Best Fuel Injector Cleaner
1. Best Overall: STP Ultra 5-in-1 System Cleaner
The STP brand produces several fuel injector cleaners but their Ultra 5-in-1 formula is by far the best. It’s designed to clean both the fuel system and injectors as well as prevent the build-up of harmful deposits.
Although expensive when compared to some of the alternatives, the STP Ultra 5-in-1 is the best fuel injector cleaner in the UK and is worth the added investment. It completely clears out the fuel system and injectors whilst also providing preventative measures to prolong peak performance.
2. Best Budget: Redex Petrol Fuel System Cleaner
Redex is a brand that specialises in additives and their petrol system cleaner is one of their most rated products. It’s designed to restore performance and reduce emissions from a single treatment to a full tank of petrol.
Overall, it’s one of the cheapest fuel injector cleaners that’s actually worth buying and it won’t disappoint. For the best results, it’s worth pouring a bottle into every full tank of fuel, which will help maintain peak performance and efficiency.
3. Best All-Rounder: Wynns 55964 Fuel Injector Cleaner
The Wynn’s Injector Cleaner is another highly rated formula that’s designed for petrol-powered vehicles. From a single treatment of the formula, the brand states that it will clean and maintain the fuel system to its optimum condition.
Overall, Wynn’s Injector Cleaner is an excellent all-round option that’s affordable and highly effective. For the best results, it’s advised that you use the cleaner every three months or every third full tank of petrol.
4. Best For Diesels: STP Diesel Injector Cleaner
Another STP injector cleaner that’s highly rated is their formula dedicated to bio and regular diesel cars. According to the brand, it’s able to unclog dirty injectors in one tankful to restore lost performance and fuel economy. For the best results, the brand recommends using this injector cleaner every 3,000 miles so that your car continues to run smoothly.
Overall, this STP formula is the best diesel fuel injector cleaner that’s relatively affordable and provides great results. It’s also produced by a highly reputable brand that specialises in additives for complete peace of mind.
5. Best Professional: Hydra Diesel Power Blast
The Hydra Diesel Power Blast is a premium fuel injector cleaner that cleans the injectors and stabilizes the fuel. According to the brand, it can be used in all types of diesel engines, which include cars, vans, boats, generators, military vehicles and much more.
Although expensive, the Hydra Power Blast is a high-quality diesel fuel injector cleaner and worth paying the extra. Considering that just 50 ml treats 50 litres of diesel, the full bottle will go a long way and won’t disappoint.
6. Best For Fast Results: Forte Diesel Specialist Injector Cleaner
Forte is a brand well-known for their highly rated DPF cleaner but they also produce a range of other additives such as this fuel injector cleaner. The “Specialist” formula is designed to provide rapid cleaning of the injectors by removing harmful deposits that have built up over time.
If it wasn’t for the expensive price tag, the Forte Specialist Injector Cleaner would be matching the STP alternative as the best. It pours straight into the fuel tank and specifically targets the injectors for better all-round performance. If the price isn’t an issue and you prefer to buy from the reputable Forte brand, their formula won’t disappoint.
How We Rated
Due to the large amount of fuel injector cleaners on the market, it can be difficult to find the best that promises results. Therefore, to help you choose the best, we have based our recommendations on thorough testing of multiple fuel additives as well as the latest research. As you can see by some of the fuel injectors we recently tested below, not all of them made it into our list above because they didn’t produce the desired results when tested.
As we own several cars, we were able to test the fuel injector cleaners on both old and modern cars as well as both petrol and diesel engines. Below are photos that display the ease of using both the STP diesel fuel injector cleaner as well as the Redex petrol fuel injector cleaner. Both simply pour straight into the tank but it’s important that you read the usage amounts per litre of fuel (labelled on the back of the bottle).
After using the STP Diesel formula in one of my diesel cars, I certainly saw an increase in miles per gallon on long motorway drives. It also distinctively started up better (particularly when started from cold in the morning). The Redex formula is one that we’ve been using for a while on many of our classic cars and we highly recommend it for regular use.
To keep up our commitment to reviewing and testing the latest fuel injector cleaners (for this article), we are continually testing the latest offerings from top brands in the UK. This means that if we notice a brand has released a new additive, we will attempt to purchase it to put it to the test. As you can see from the photos below, we are regularly testing both petrol and diesel injector cleaners to ensure our recommendations are still the best.
To give you an idea of how easy the fuel injector cleaners are to use, below is a video we posted on our YouTube channel that shows us emptying in the STP formula into our fuel tank for testing.
As well as testing the latest fuel injector cleaners and plenty of research, our recommendations are also rated based on their cleaning abilities, brand reputability, treatment duration and value for the money.
Fuel injector cleaners have been proven to work and they can completely change your car’s performance. From a sharper throttle response to improved fuel economy, there is a list of improvements that can be made.
All of our recommendations above are suitable for both diesel and petrol cars and they simply pour into the fuel tank. However, for the best results, it’s advised that you pour the cleaner into the tank before filling the tank up.
If you require further information with regards to any of the fuel injector cleaners listed in our roundup, feel free to get in touch and we will try to provide our assistance where possible.