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HYDRA MAXIMUS Cleaning Diesel Injectors, Diesel Turbo Cleaner, Use the Best Fuel Injector Cleaner Additive for Diesel Fuel

Our Price:  £9.95(Inc. 20% VAT)(£8.29 Exc. VAT)

Diesel Improvers / Injector Cleaners Comparison 

Brand:  HYDRA

  (25 Reviews)
  • 500ml Treats Up To 250L of Fuel
  • 5 Litre bottle comes with free dosing bottle
  • Maximum Performance
  • Maximum Fuel Efficiency
  • Maximum Lubrication
  • When Only the Best Will Do 
  • Turns Regular Diesel into Premium + + + Diesel, this is much better than any available filling station premium product

Feature & Advantages

  • 500ml Treats Up To 250L of Diesel Fuel.
  • 5 Litre bottle comes with free dosing bottle.
  • Maximum engine performance, additive for diesel fuel 
  • Maximum fuel efficiency 
  • Maximum Lubrication with Reduced Friction  
  • Turns Regular Diesel into Premium + + + Diesel, which is much better than any available filling station premium diesel fuel.
  • When Only the Best Will Do! 


Hydra MAXIMUS, we cannot claim it gives your car a jet engine, but with its instant pick-up, smoothness, and power it will certainly feel like one. The best diesel fuel additive you can buy.

Modern diesel engines use high pressure fuel pumps with a pressure of up to 44,000 psi, the fuel is forced through tiny holes in the injector. This high pressure and tiny jet size create a very finely atomised mist of fuel. Creating a fine fuel mist ensures that each molecule of fuel is surrounded by many molecules of air, which contains 20% oxygen. This ensures an efficient fuel burn.  

When the vehicle is new, this process works very efficiently, and the diesel engine operates at optimum performance as designed by the manufacturer. However, over a period of time (within 2,000 miles) deposits of carbon and unburnt fuel start to build-up in the injectors interfering with the correct spray pattern resulting in fuel wastage and higher emissions due to unburnt fuel leaving the engine.

Also, diesel fuels with cetane numbers lower than minimum engine requirements can cause rough engine operation. They are more difficult to start, especially in cold weather.


Many low cetane fuels also increase engine deposits resulting in more smoke, increased exhaust emissions and greater engine wear. The black smoke consists of carbon compounds that have not burned because of local low temperatures when the fuel is not fully atomised.

Low cetane levels in diesel fuel can also result in engine damage over time. When the cetane number of the fuel is low, engine knock and starting trouble can result from delayed ignition. Diesel knock can also occur during idling, giving poor warm up and white smoking after start-up.

These local low temperatures occur at the cylinder walls, and at the surface of large droplets of fuel. At these areas where it is relatively cold, the mixture is rich (contrary to the overall mixture which is lean). The rich mixture has less air to burn and some of the fuel turns into a carbon deposit.

Using fuels which meet engine operating requirements will improve cold starting, reduce smoke during start-up, improve fuel economy, reduce exhaust emissions, improve engine durability, reduce noise and vibration.

Modern high pressure, direct injection diesel engines need high cetane levels to operate at their optimum efficiency. By decreasing the ignition delay, Hydra MAXIMUS gives more time for the diesel fuel to burn and lowers the pressure inside the chamber.

With a better fuel combustion at lower pressure, massive fuel and emission savings are possible.

Hydra MAXIMUS contains the maximum level of cetane booster to ensure that ordinary diesel is turned into Super +++ grade much better than you can buy at the filling station.


A diesel fuel injector cleaner must contain powerful detergents and the best diesel additives contain polyetheramine as in Hydra MAXIMUS these prevent the formation of and, also removes existing deposits caused by fuel decomposition and unburnt fuel down to molecular levels. These deposits interfere with the performance of your diesel engine.


Injector deposits also mean uneven fuel flow, whereas 100% clean injectors give optimal fuel spray pattern resulting in a very finely atomised spray. This atomised spray means that each finely dispersed particle of fuel is surrounded by many molecules of air (20% oxygen) ensuring a more complete burn.

This in turn gives you much better fuel economy, as all the fuel is burnt, reducing emissions, and improving engine durability. By reducing soot formation Hydra MAXIMUS also helps keep the diesel exhaust gas return valves clean, acts as a diesel turbo cleaner giving the engine as new performance.


A good diesel fuel cleaner like Hydra MAXIMUS also contains lubricity improvers, that extend the life of injectors and the fuel pump. These lubricants work in very cold climates and do not raise the sulphur level of treated fuel.

Test results give HFRR Wear Profile of less than 300. Our lubricants also reduce the friction in the cylinder thereby improving the coefficient of friction helping fuel economy. Hydra MAXIMUS protects your valuable fuel systems, prevents engine malfunction and engine failures.


Modern high pressure direct injection engines use precise fuel metering through narrow shaped spray channels. Injector deposits mean reduced fuel flow. 100% clean injectors give optimal fuel spray pattern, this results in a very finely atomised spray pattern.   

This means that each finely dispersed particle of fuel is surrounded by many molecules of air (20% oxygen) ensuring a more complete burn. Giving better fuel economy, reduced emissions, and improved engine durability.


Hydra MAXIMUS’s nano-molecular catalyst ingredient introduces additional oxygen to the fuel, this catalyst lowers the auto-ignition fuel temperature, giving a longer burn time.

You are now burning all the fuel instead of blowing some of it through the exhaust system where it will help clog the Exhaust Particle Filter if fitted. The net result is a quieter and smoother running engine with more mpg and reduced exhaust emissions.


The problem with diesel fuel used in boats, generators, farm vehicle etc., is that very often this fuel remains in the fuel tank for extended periods before being used.

As many of us are aware this fuel starts to degrade after only 4 weeks, leading to long term problems and inefficiencies (in a car it is normally used within a week or two).

Hydra’s stabiliser and biocide active ingredients ensure that your fuel remains sweet and stable for much longer.


Independent Laboratory Tests proof that treated diesel still meets EN590:2009 the current EU standard for diesel fuel, therefore your vehicle warranty is not affected by using Hydra MAXIMUS which is the best fuel injector cleaner in the UK.


  1. The most cost-effective additive for diesel engines, to ensure your engine is running at its peak efficiency and economy.
  2. A UK formulated and produced diesel engine additive.
  3. When you need to use a cat cleaner in diesel engine fuel injector cleaner to ensure your diesel engine is running at peak efficiency.
  4. Which is the best diesel cleaner that you can buy? 
  5. How you can you find the best diesel booster for maximum performance from your engine?
  6. How to find the best diesel engine cleaner available today.
  7. How often is diesel engine injector cleaning carried out?
  8. How often should you use a diesel engine treatment. is it every time you refuel?
  9. Diesel engine injector cleaner which is the best one to use?
  10. Which is the best diesel turbo cleaner, that everybody uses?


Use Hydra MAXIMUS it has been designed to overcome all these problems. Product reviews are outstanding, and we do not think that there is a better product on the market.


Dose Rate: 1:500 Use 2ml Hydra MAXIMUS to 1 litres of fuel.


All our products are manufactured to the highest specifications at our UK plant, which is accredited to ISO 9001:2015, ISO 14001:2015 and ISO 45001:2018.

How To Use: Maximus Diesel Power Booster

  1. Remove filling tube from the bottle.
  2. Open the cap on filling chamber and pierce the seal. 
  3. Tightly fit filling tube on the bottle, remove closure from the top of the tube and gently squeeze the bottle to fill the filling chamber with product.
  4. Pour the product directly into your fuel tank, repeat if necessary.
  5. Close the bottle with original cap and store upright to avoid spillage.

Pour directly into fuel tank before or after refueling.

Use only for DIESEL FUEL.

Dose Rate: 1:500 Use 2ml Hydra MAXIMUS to 1 litres of fuel.

When should you use a diesel engine fuel additive?

To ensure your engine at its peak performance to get the maximum benefits you should use every time you refuel.

Who makes the best fuel additive for diesel engines in cars, vans, generators, trucks and boats?

Hydra MAXIMUS, this brings your treated fuel to the best premium grade that you can buy.

Which is the most cost-effective fuel conditioner on the market?

To stabilise you fuel always use Hydra MAXIMUS.

How can you do a diesel additive test without any equipment?

Simply use your cars mpg trip computer on a regular basis and if your fuel consumption increases then it is time to use a diesel fuel injector cleaner.

Which is the most popular fuel cleaner additive available in 1 litre dosing bottles?

Hydra MAXIMUS is used in many tuned diesel vehicles which require a premium fuel to run properly.

Who makes the best diesel fuel injector cleaner, which has lots of 5 stars reviews?

Just look at Hydra’s many 5-star reviews from the different channels we sell on.

How makes the best diesel fuel tank cleaner, that is available for next day delivery in the UK?

Hydra as a manufacturer of fuel additives we always have these products in stock for a next working day delivery service.

Why you need the best fuel system cleaner available?

You need to make sure that you are buying a concentrated all in one cleaner, that contains detergents, cetane boosters and lubricants this will ensure that you get the best possible fuel system clean.

Which product receives the best diesel injector cleaner reviews?

The Hydra range of diesel additives supplied direct from the manufacturer at the best possible price.

I want to use a diesel emission reducer how often should I use it?

To get the best benefits from a it should be added to your diesel fuel every time you refuel.

I have an MOT due shortly, so when is the best time to use a diesel emission reducer?

Add it to you fuel tank a couple of weeks before the MOT is due, this will give the additive plenty of time to work and clean out your complete system.

Where can I buy the best fuel injector cleaner for diesel fuel?

If is available on the internet is available now, in the UK for next day delivery by courier.

Do diesel additives work, or are they snake oil?

A correctly designed fuel additive manufactured by a reputable company, will contain cetane boosters, detergents and lubricity boosters and you will definitely feel the difference within the first tank of treated fuel.

Average Rating (25 Reviews):  
Write a Review and share your opinions!

Hi There
Friday, 16 April 2021  | 

I am writing to let you know that I have recently purchased the HYDRA Maximus Power Booster to try in my Mini Cooper 2.0 SD which I virtually always fuel with Shell V power diesel. The car is not used daily but when it is I usually drive 25-30 miles across country on A and B roads to get to my destination. I bought the 500ml size as I was unsure as to it's effectiveness but I have to say that I noticed an almost immediate change in the driving experience and I'm already on my second tank using Maximus! I can honestly say that there has been a very real improvement in the performance of the vehicle. It picks up quicker and overall provides a far punchier experience than standard. The car feels far more eager between bends and the mid range "thump" is impressive. There is a significant difference in everyday driving as the car feels quieter, smoother and doesn't need to be worked so hard. I'm not particularly interested in economy figures and cannot confirm any improvements in that area but I am certainly happy with the improvements in driving dynamics. I will be buying this product from you again! I'm not usually given to writing to companies endorsing their products but in this case I am happy to say that it works and works very well...Thanks!

Was this helpful to you?  Yes  /  No

5 of 5 people found this review helpful.

Good Afternoon,
Wednesday, 9 December 2020  | 

I received my order within 2 days of ordering, it was well packaged, items i ordered were in the package, i have used one of the fuel additives and it appears my car is running smoother now, very pleased with your Company, and the products you sell on Hydra Aqua,
Customer Service is Excellent.
Thank You, Hydra International.


This review has not been appraised.

Friday, 18 September 2020  | 

My feedback is always the same. As per many positive reviews of your product, you used to supply these bottles with a reinforced ziploc bag which was perfect for storing them (once opened) in my car. I haven't been able to find a similar bag anywhere else and wish you would return to including one with each bottle purchased.


P. Hegan


This review has not been appraised.

New Review
Friday, 18 September 2020  | 

Great transaction, very impressed with every aspect,
Thank you


This review has not been appraised.

Saved me 3000
Sunday, 6 September 2020  | 

I had a problem with white smoke puffing out my exhaust on start up. Subaru said it was diesel injectors and quoted 3000 because its an engine out job. I bought the diesel injector cleaner and after 1 month of use the smoke has all but gone. I was averaging 500 miles to a tank and since using this I'm now getting around 630 miles to a tank. I'm not saying everyone will be as lucky as me but for the cost of this product it's been amazing. Pretty much saved my car from the scrap heap.


This review has not been appraised.

Wednesday, 2 September 2020  | 

Many thanks for the very quick service. I should have brought the 500 ml brought the cetane boost for that price.also purchased diesel fuel cleaner. Have put both in vehicle and hopefully it's working it's magic as we speak.


This review has not been appraised.

New Review
Tuesday, 7 July 2020  | 

Hi guys, have had your fuel additive before very pleased.. As a retired vehicle technician l can feel the difference. The engine responds with less throttle demand....


This review has not been appraised.

New Review
Thursday, 18 June 2020  | 


Ordering and delivery is simple and efficient as usual.

As for the product itself I have now increased the dosage to 2.5ml per litre (rather than the recommended 2.0/litre). And this is a lot better.

I have seen fuel consumption improve by around 10% overall. And my car (9 year old Audi Q5) is running like new.

The only problem that remains is your awful dispensing bottle. I decant the product into little (200ml) fruit juice bottles with sports cap and this works very well.

all the best
Jonathan Holloway


2 of 2 people found this review helpful.

I don't know if is working or is placebo effect
Thursday, 12 March 2020  | 

The engine runs quiet a little bit but..... that's it. Consumption went up .


This review has not been appraised.

Tuesday, 3 March 2020  | 

This stuff is brilliant. I do between 3 -400 miles per week in my 59 plate Ford TDCi with 115k on the clock. I've used the Hydra Injector Cleaner over the past 12 months and I rate that, this is even better.
Engine is quieter with smoother power delivery, it just keeps pulling (especially at the top end, perfect for my A-road commute).

The only downside is that its addictive, after using it once I never want to run my car without it.


This review has not been appraised.

Read all 25 customer reviews...