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HYDRA MAXIMUS is a premium 1-litre diesel fuel injector cleaner and additive that treats up to 500 litres of diesel. Featuring polyetheramine and cetane boosters, it aggressively removes carbon deposits, cleans turbo and EGR valves, and lubricates fuel system components. Designed for highly tuned diesel engines, it improves cold starts, reduces emissions, smooths engine performance, and extends engine life — making it a must-have for diesel drivers aiming to maintain peak power and fuel economy.










| ASIN | B07RN8HZH3 |
| Best Sellers Rank | 13,968 in Automotive ( See Top 100 in Automotive ) 147 in Fuel Systems |
| Brand | HYDRA |
| Customer Reviews | 4.6 4.6 out of 5 stars (250) |
| Date First Available | 9 May 2019 |
| Delivery information | We cannot deliver certain products outside mainland UK ( Details ). We will only be able to confirm if this product can be delivered to your chosen address when you enter your delivery address at checkout. |
| Item Weight | 1.2 kg |
| Manufacturer | Hydra International Ltd |
| Manufacturer part number | HYD63906 |
| Manufacturer reference | HYD63906 |
| Package Dimensions | 27.1 x 19 x 10.7 cm; 1.2 kg |
G**S
Great quality products
This additive definitely does something to the car, there is a fuel saving, but not huge, the big thing for me is the result it has on the engine, with the additive the engine is so much quieter and a lot smoother. Running a 110000 diesel Vauxhall so like to look after the engine. I have been using this company's additives for over a year now and rate these over the big name brands 100%
L**M
Excellent product
Used on a 2007 2.2 Honda Civic i-CTDi. The car always ran pretty smooth due to years of filling up on Shell V-Power diesel. Put this product in with normal diesel and the difference was immediately noticeable. Works out cheaper to buy this and add it to normal diesel than buying premium diesel. Been using this product a few months now after every fill up. Car is more responsive when setting off. Lower revs gives more torque now. BHP has increased when tested. City driving MPG has also gone up by around 8 MPG. The bottle is an awful design and can easily leak. You don't want to keep this product in your home or car though as it is very smelly! The only thing this product DIDN'T do as claimed is clean the EGR Valve. Which was just as filthy as before I started using Maxiumus. Maybe you have to use it for a long long time before it would have any effect on EGR. I will continue to use as it is the best fuel additive I've ever used.
G**4
Car is running much better
I run a 6 year old Renault with the 1.6dci and on the whole it’s a great engine. Since buying the car 6 months ago I’ve changed all the fluids and filters and the car runs perfectly, however I’ve always felt that it was very flat lower in the rev range. Like others I’ve previously used Millers additives in my Diesel cars and can’t say I ever felt much difference so this time I decided to try Hydra’s product - what a difference!! Since adding this at the recommended dosage the car feels noticeably stronger at lower rpm and my mpg has increased by 3mpg on average. I’m now able to drive in higher gears without the engine feeling like it’s labouring all the time and the pickup in any gear feels much better. My engine was always quiet and smooth enough for a diesel, I’d say it’s running a tiny bit quieter and smoother but given my car wasn’t running badly anyway it’s hard to be sure as the difference is so slight - certainly it’s had no negative effect on this at all. Totally agree with the other reviewers, for the price give it a go - it’s not a lot to loose if it doesn’t work for you, but going by my experience a whole lot to gain when it does! I’ll certainly be buying more Maximus going forward. Well done Hydra this is a great product.
A**O
Well worth the buy
This product is essential for anyone who owns a diesel vehicle and it works out cheaper to use this combined with regular fuel rather than using the premium fuels at places like shell or BP. When I last used some of this it literally felt like my vehicle had had a performance modification.
D**E
Great product
I was very sceptical about this product and the claims it makes I’ve been using it now for about 2 months and my van a 2014 vw crafter has got improved performance the acceleration is massively better and I am getting about 50 - 60 miles to the tank more than before The product does have a strong smell to it when your putting it in but not when you drive I would definitely recommend this and will be buying more
G**H
Brilliant stuff!
Brilliant stuff. Actually does make a difference, after a couple of tanks with this in the engine sounds a lot smoother and feels like it picks up marginally better, it's also much cheaper than buying premium fuel. I've tried many different fuel additives, liqui moly, wynns, stp and a couple of others but this is by far the best.
A**R
Trust The science
Right, to begin last year in July I bought a Range Rover L322 with the 3.6tdv8. The car didn’t run poorly when I got it. But when the quoted mpg from the manufacturer is 25mpg, you do whatever you can to keep it that way. After some cleaning of sensors etc… general maintenance. I began adding this to the tank. The mpg I have been getting now is around 30. With mixed local and distance driving. The real improvements come from the response of the engine and the reduced rpm it runs at to maintain speed. Those improvements are worth the price of admission for me. It does work but the biggest contributor to mpg is your right foot.
M**P
Very good product
Very good stuff, I would recommend.
G**E
È un ottimo prodotto e posso garantire che già dopo i primi 100 km si vede la differenza,migliore risposta di coppia, motore più fluido anche ai bassi regimi. Continuerò ad usarlo. Sul prezzo purtroppo è vero è un po altino ma sono soldi spesi bene per far vivere più a lungo il motore e le sue parti. Mi sono accorto in più che ho consumato meno additivo Adblue a parità di km e tragitti fatti quindi il prodotto funziona per me. Sui consumi dipende da come la si porta l autovettura cmq un minimo c è di riduzione ma capite bene che le prestazioni saranno superiori a parità di motore.
A**R
Experimentiere seit Jahren mit verschiedenen Produkten. Maximus hat mich beeindruckt. Meine Mixtur ist 1:1000 Zu Beginn etwas höher dosiert. Wir verwenden es bei einem BMW 320d Mercedes Sprinter 316cdi und einen Ford Transporter Fazit: Der Motor geht schneller auf Drehzahl, der Turbo beginnt früher Leistung aufzubauen. Besserer Kaltstart und ruhiger Motorlauf. Wir haben ca.0,4 Liter weniger Spritverbrauch als vorher. Ist bei uns im Dauereinsatz, saubere Verbrennung,gute Abgaswerte. Bin sehr zufrieden.
A**O
Lo estoy usando, esperaré a comprobar que tal va. Aparente mente va bien
C**N
Después de usar todo el contenido no he apreciado una disminución el el consumo de gasoil. Sí he notado una mejora de suavidad en el motor. Por otro lado una vez abierto desprende un olor bastante fuerte, y dado que lo llevo en el maletero cada vez que abro el maletero el olor es molesto.
M**O
Veramente ottimo
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1 month ago
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