Does Redex Work – Redex Fuel System Cleaner Real-World Test

Redex and its fuel system cleaner solution – for petrol and diesel engines – is designed to remove injector deposits and improve fuel economy. However, does Redex work? Well, after quite a bit of testing with 3 months’ worth of Redex fuel system cleaner with our 2.2-litre diesel Range Rover Evoque, its effects are certainly more noticeable in older, high-mileage cars.

To learn more about how Redex fuel system cleaner could help save you money by improving your car’s fuel efficiency, here’s what we’ve found:

Redex System Cleaner

Just as you wouldn’t leave your car interior or bodywork dirty for months on end, you shouldn’t take liberties with your engine. Fuel economy can be reduced by the deposits which build up on your fuel injectors during combustion.

This is a result of the varying fuel qualities available in the UK and the amount of additives they contain. The resulting build-up means that you’ll be paying more for fuel, as your injectors won’t be working as efficiently as they should.

Redex Fuel System Cleaner eradicates this deposit build-up. Regular use will keep the injectors in their best working condition and save you money when driving. We’ll be adding Redex to our Evoque every time we buy fuel for 3 months, and posting updates about how it’s working throughout.

Benefits Of A Fuel System Cleaning

Redex offers a premium brand solution to improve fuel economy. The fuel system cleaner, available for both petrol and diesel cars, promises to keep both your fuel consumption and emissions low. This means the product is not only great for your car, but great for the environment too.

The benefits extend beyond saving you money on fuel, though. This reduction of harmful emissions could mean your vehicle is a step closer to passing its MOT, meaning even less money is spent on repairs to make it roadworthy.

Redex Fuel System Cleaner will improve engine life and restore the best possible performance to your vehicle. It means cars can drive further on their fuel, and give you a healthy car on the inside. Better yet, Redex is the number 1 market leader in UK fuel additives.

A Range of Easy-To-Use Products

Redex doesn’t stop at petrol and diesel cars. The system cleaner is also available for hybrid vehicles, which burn similarly to petrol engines in terms of injector build-up. Additionally, Redex offers a range of other products, from Adblue, which helps reduce diesel car emissions by up to 80%, to Lead Replacement.

The latter means you can use unleaded petrol in leaded cars, especially classic vehicles, so the engine receives the additives it needs. Using unleaded petrol in a leaded engine can inevitably lead to major problems – Redex eliminates that threat.

Redex System Cleaner is really simple to use. Just add 90ml of the cleaner to your fuel tank every time you refill the tank. If you haven’t used any fuel additives in a while, it’s a good idea to first add a double dose (180ml). This will clean the engine thoroughly before regular use.

We’re excited to see the results of Redex System Cleaner on our Evoque. Remember to check back for our updates and review!

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Update 2

For the past month, I have been testing Redex System Cleaner in a 2.2 litre Diesel Range Rover Evoque, and I have been carefully monitoring the results and the benefits I have experienced from the product.

What Problem Does It Solve?

Redex is known to be good for maintaining your engine and removing deposits from fuel injectors. Fuel economy can be reduced by the deposits that build up on your fuel injectors during combustion, Redex System Cleaner eradicates this deposit build-up.

How Redex Helps

You add the Redex System Cleaner into your fuel tank to mix with the petrol or diesel. The cleaner promises to keep both your fuel consumption and emissions low. This is achieved by removing the deposits as the fuel and Redex mix passes through the injectors.

Used regularly Redex System Cleaner can improve engine life and restore the best possible performance to your vehicle. It could mean cars can drive further on their fuel, and give a healthier car on the inside.

Does Redex Work?

So, I am testing the Redex on a car that is 4 years old. I am guessing that there isn’t a huge amount of deposit build-up on the injectors from the 30,000 miles it has done during its time on the road.

But after using the first shot bottle of Redex and completing the first 400 miles until the tank was empty, I felt good knowing that I was taking care of the inside of the engine and removing any deposits that may be degrading performance.

On the second and third tanks of fuel, I did notice slightly increased total mileage per tank, but of course, it is very difficult to prove that the Redex System Cleaner was the factor that influenced the extended range, but it definitely wouldn’t cause a decrease in total range.

I can’t say I have felt any dramatic performance increases in the car at the moment, but in a car of this age, we could be talking about a 2% or 3% improvement at best.

You are likely to see more noticeable results from the Redex System Cleaner when used on vehicles at least 10 years old or those that have done higher mileage and have had more opportunity for the deposit to build up.

I’m sure in these cases you would be able to feel a definite difference in a short period of time, for our test it will be a lot more about the prevention rather than the cure.

Continued Testing – Does Redex Diesel Work

I am going to keep testing the Redex System Cleaner on my Evoque Diesel and see what I learn over prolonged testing. Even if there are no further gains to be had, in my opinion, it is still good practice to maintain a low level of deposits on the car injectors and keep the engine running as optimally as possible.

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Update 3

We’ve been testing Redex System Cleaner for two months now. Our 2.2-litre Diesel Range Rover Evoque has been having the Redex treatment, and is a lot better off for it.

The Benefits of a System Clean

Redex System Cleaner helps maintain and improve the condition of your engine and removes deposits from your fuel injectors. Harmful buildups on the injectors occur during combustion – Redex helps to eradicate this. Simply add 90ml of Redex to your fuel tank every time you top up; or, if you haven’t used a system cleaner in a while, add a double dose.

Used over time, Redex can improve both engine life and vehicle performance. You get better fuel economy, meaning you get more fuel and more miles for your money. As simple a thing as adding a bit of Redex System Cleaner to your fuel tank can save you money and hassle in the long run. The product also claims to help reduce harmful fuel emissions – so by giving your engine a good clean, you’re also helping the environment.

Redex System Cleaner & Does Redex Work (?) – The Verdict

The car we’ve been testing the product on is 4 years old, with a mileage of just over 30,000. This meant the car probably didn’t have too much buildup on its fuel injectors. However, after just one shot of Redex, the Evoque just felt healthier, and knowing performance wasn’t being degraded over the 400-mile journey put our minds at rest.

We noticed slight increases in mileage per tank after the second and third additions of Redex. This, of course, can’t be definitively put down to the system cleaner, but it certainly didn’t hurt. Since our car is relatively young, the best we can expect is a 2-3% improvement in performance.

For older cars, say 10 years or older, you can experience more drastic improvements as the fuel deposits will have had more of a chance to gather.

That’s not to say it’s a bad idea to use Redex on a younger car. The cleaner can keep the car operating at an optimal level, preventing buildup rather than fixing it.

Redex Fuel Economy Test – Before & After Results

Once again, to summarise our testing on does Redex work and determines whether it improves fuel economy, here’s a reminder of our testing methodology:

• Vehicle – 2.2L Diesel Range Rover Evoque
• Baseline – Measured mileage over three full tanks before using Redex
• Treatment – Added the recommended 90ml of Redex per refill
• Duration – 3 months (approximately 12 full tanks)
• Driving Conditions – Mixed urban and motorway driving

With that in mind, here’s a quick summary of our results:

Stage	Total Miles Per Tank	Average MPG
Before Redex (Baseline)	480 miles	38.4 MPG
After 3 Tanks with Redex	495 miles (+3.1%)	39.6 MPG (+3.1%)
After 6 Tanks with Redex	502 miles (+4.6%)	40.2 MPG (+4.6%)
After 9 Tanks with Redex	508 miles (+5.8%)	40.8 MPG (+5.8%)

Here’s what we can learn from this:

• After 9 tanks, we saw a 5.8% increase in miles per tank compared to the baseline.
• Redex doesn’t provide an instant boost, but consistent use showed a noticeable improvement and gradual gains over time.
• We expect that cars with higher mileage and that are older (10+ years old) may see even greater benefits than newer cars.
• While the difference isn’t massive, it helps maintain efficiency and could lead to savings in the long run as a preventive tool.

Does Redex Work: The Final Say

Overall, we haven’t noticed any extreme changes using Redex over the past few months. However the idea of a system clean is still a good one, though. Redex provides preventative measures for keeping fuel tanks clean and can improve fuel economy over time. We really like the idea of using a cleaner regularly as a way of maintaining the vehicle. After all, we like to keep the bodywork clean and polished – why not the engine too?

In conclusion, based on our three-month test, Redex offers preventative maintenance rather than dramatic performance gains. If you drive a high-mileage or older car, you might see noticeable improvements, but for newer vehicles, Redex is best used as a maintenance tool rather than a fix. So, in short Redex does work, particularly on older or higher-mileage cars.

Misconceptions About How Does Redex Work

Despite being a well-known fuel system cleaner, there are several myths and misunderstandings about how does Redex work. So, let’s clear up some of these myths:

1. “Redex Is an Octane Booster”

• 🚫 False – Redex does not increase your car’s fuel octane rating.
• ✅ Truth – It helps with cleaning your fuel injectors and prevents carbon buildup, which may improve combustion efficiency, but it won’t make regular fuel behave like premium fuel.

2. “Redex Instantly Improves Acceleration and Power”

• 🚫 False – Adding Redex to your fuel tank won’t suddenly make your car feel more powerful.
• ✅ Truth – Redex helps maintain engine efficiency over time by keeping your fuel injectors clean. If your car had performance issues due to injector deposits, you might notice a smoother throttle response after multiple treatments, but it’s not an instant power booster.

3. “New Cars Don’t Benefit from Redex”

• 🚫 False – Even new cars can develop carbon buildup, especially if driven short distances frequently.
• ✅ Truth – While older, high-mileage vehicles tend to see the most noticeable benefits, using Redex regularly in a newer car can help prevent deposits from forming in the first place, maintaining optimal performance.

4. “Using Redex Too Often Can Damage Your Engine”

• 🚫 False – Some drivers worry that frequent use of fuel additives can be harmful.
• ✅ Truth – Redex is formulated to be safe for regular use and is recommended at each fill-up to keep injectors clean. However, excessive use (such as pouring in more than the recommended dose) is unnecessary and won’t provide extra benefits.

5. “Redex Can Fix a Failing Engine”

• 🚫 False – Redex is not a miracle cure for major engine problems.
• ✅ Truth – If your engine has mechanical issues, like a failing fuel pump or clogged EGR valve, Redex won’t fix them. It’s a preventative maintenance product, not a repair solution.