HYDRA FD-66: Fuel Dryer & Ethanol Stabilizer
 Pack Size: 250mlPack Size: 500ml 

HYDRA FD-66: Fuel Dryer & Ethanol Stabilizer

Our Price:  £10.95(Inc. 20% VAT)(£9.13 Exc. VAT)
Pack Size:

  (8 Reviews)


  • 500ml Treats Up To 150L of Fuel
  • Eliminates water from the fuel tank
  • Protects against rust and corrosion   
  • Prevents carburettor and fuel system icing
  • Suitable for petrol and diesel engines
  • Absorbs water into all fuel types where it is simply burned in the engine during the normal combustion process.

Brand:  HYDRA

  • Eliminates water from the fuel tank.    
  • Protects against rust and corrosion.     
  • Prevents carburettor and fuel system icing.     
  • Suitable for petrol and diesel engines.


The amount of ethanol found in fuel has been steadily increasing over time, this is because the ethanol acts as a combustion aid which helps in cold starts and reduces carbon dioxide emissions when the engine is too cool for efficient combustion.

However, a common problem with these high ethanol fuels is that they suffer high sensitivity to water contamination, which can cause fuel to separate out into corrosive acid and hydrocarbons.

This corrosive acid is incredibly harmful to engines and other metal components found in the fuel system, making water contamination a serious issue. To make matters worse the level of water in your tank only needs to be 0.06% for phase splitting to occur.


Another issue with water in the tank is the dreaded ‘Diesel Bug’

The Diesel bug is a single or group of microorganisms that grow in fuels. They include bacteria, mould and yeasts and grow in water contaminated systems feeding on hydrocarbons and destabilising fuel.


This is where Hydra FD-66 comes in, this fuel dryer and ethanol stabiliser breaks down the surface tension between water and fuel, absorbing all excess moisture that accumulates from tank condensation, and then holds it in suspension until it is burned away by the engine during normal operation.

For effective treatment use 10ml for every 3 litres of fuel in a 10:3000 ratio, and retreat every 6 months at refuel. Best used in conjunction with our Bug test kit, so you can determine if our system has been affected and then effectively treat the problem before damage to your engine can occur.


All of 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.


Diesel Bug Incubator and Test Kits

How does it eliminate water from the tank?

It absorbs it into the solvent, where it is burnt in the engine.

Can this be used in a 4 stroke petrol boat outboard?

Yes, it is ideal for this application.

Bought this product along with FPB-77 after buying Diesel that came with a side of water. Can I use them together?

Yes, you can use them together. 

Average Rating (8 Reviews):  
Write a Review and share your opinions!

Water problem gone
14 October 2019  | 

Within one application of this product my water problem in my fuel has dissapeared. I am so impressed that I have bought another bottle for the future.

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3 of 3 people found this review helpful.

Another fantastic product by Hydra
14 November 2018  | 

I use this product in mine and my wifes car which are both petrol and diesel as well as my motocycle. It has great results especially in my motocycle that over winter sits in the garage with a full tank of fuel and Hydras, FuelPlus to eliminate bugs. I add this product ready for use in the spring/summer months.


This review has not been appraised.

What a treat
03 September 2018  | 

My fuel filter light came on about 2 weeks ago so I researched products to help solve my problem. After purchasing and receiving my product the next day and well packed, I added it into my fuel tank and within minutues the light dissapeared. I highly recommend this product as it worked a treat for my car.


This review has not been appraised.

Surprised and fantastic product
14 May 2018  | 

After a ruined holiday away in my motorhome and being towed back home. I went to the garage where they said my fuel tank needs to be drained due to water in the fuel. I was told about Hydras' Fuel Dryer which I thought this could not work but I bought a bottle anyway and added it all to the fuel tank. I took it for a drive allowing for the product to swoosh around, and within 10 minutes the engine was starting to run a lot smoother. By the time I got home everything was as good as new. I could not believe it worked and how much money I have saved from not getting it done by the garage. I will be keeping one in the motorhome for future in case I come into this problem again. I can now plan our trip away again now.


This review has not been appraised.

Great product with no stalling & no misfires.
01 April 2018  | 

After using cheap fuel that contains water in my car was having problems first with misfires and stalling and then not starting. I saw this recommended on google and was a hell of a lot cheaper then getting the fuel tank drained. I put this in and it started up with no problems, no stalling and no misfires. 100% works.


This review has not been appraised.

Magic Product
21 March 2018  | 

This product is magic. It has made such a difference and has improved the performance of my Passat. I will definitely be buying again if the problem occurs again.


This review has not been appraised.

EML showing no more
11 February 2018  | 

Often my diesel Nissan would power less with the EML coming on. My husband said it could be water in the tank so he ordered me a bottle of this product. When I fuelled up and put the product in, within minutes the power had rocketed and no more EML on. I am extremely pleased with the results and no more worry on the car breaking down.


This review has not been appraised.

Converted sceptic
17 May 2017  | 

My dirt bike was having issues with water in the fuel tank so I bought this product after reading good reviews. I tested it out first in a glass test being reluctant it would work but it did. After this positive test I put it in my bike and took it for a run...I am amazed it has worked. I highly recommend this to anyone with water problems in your tank.


This review has not been appraised.

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