Hydra EHN-99

It has taken a while for me to write this review but can now confirm that this works.It has increased my average fuel consumption by 2,4mpg, that may not sound a lot but that is considerable. The other benefits include smoother running and more power making the car better to drive in all circumstances. The vehicle in question being a Volvo V70 D5 with over 150000 miles covered,my average fuel consumption now being 52.9mpg and that is mainly town work. Also my emissions for the MOT were lower than required. I have been precise with dosing, i use a syringe to be accurate. The benefits of this product are real, i have tried them all over the years but this one works, pays for its self.

I use this alongside their DPB-100 fuel additive, in a high mileage 2009 Audi A4 2.0 TDI ….. before ever using this, I would struggle to achieve over 55mpg on long runs. Ever since dosing my fuel with 30ml of this and 30ml of DPB-100 (to a 60L tank), my MPG has increased and I’m now able to comfortably achieve 65mpg on long runs with the same driving style. Whenever I forget to dose my fuel with this stuff, I see a reduction in MPG to around 60mpg…… so it’s helped improve the economy even when there’s none in system. Overall, my economy is up by 18% since before I used it. A new MAF sensor may also be attributing to that figure, but what cannot be denied is the 8% to 10% improvement in MPG I see between having fuel treated with this and without it. I spend £3000+ a year on fuel, as I do a lot of miles, so an outlay of approx £50 a year on this stuff and the DPB-100 is saving me between £200-£250 a year, as well as having the peace of mind that my engine is running optimally. Also….. I’ve found that it improves supermarket diesel the most, so if you usually use shell or one or the more expensive places, you can save more going for the cheaper supermarket stuff and still see a similar return at the pump. I feel 65mpg for a medium sized 14 year old car with 146,000 on the clock is pretty good going! Treating your fuel with this, ensuring tyre pressures are correct and sticking to 60-65mph on the motorways you’ll save hundreds every year!

This is amazingly smelly stuff but I kid you not it's a bargain and we'll worth the money I bought 1ltr bottle for a test and no lie I normally put £40 of BP diesel and get roughly 130 miles of actual driving but the dash recons 200 miles I drive smooth in city I get bad mpg but rural which I do regularly 70miles a day I get fantastic mpg, I added 0.5ml per ltr of ehn-99 first time and noticed slight improvement on fuel then came the second time 1ml per ltr and oh my gosh I have driven the actual 200 miles and still have 60miles to go I had to share this review, my mpg hasn't changed on dash but actual fuel consumption on eco mode or driving smooth is fantastic and if you have led foot I tell ya what this is your buddy. Your fuel tank will stink when filling up like a stink bug smell and as you pour in if you get any on you it's a massive effort to get rid of the smell of you skin, but I swear if you use it right and wear gloves or be careful you will love this stuff. My next purchase will be maximus but for now I think I could drives for miles and miles and not need to look at my fuel gauge. Its well worth it

It seemed to improve the performance, so all good.

Definelty adds power to my car, its more responsive, the engine runs smoother and the fuel consumption dropped . I've tested it for the first time yesterday on a 300 miles journey and wow, what a great additive. The fuel consumption decreased by decreased by 3 miles to the gallon. Most noticible is the engine noise being lower and the power of the engine.

Only just got the item , I do alot of mileage so I with thoroughly test this and update in future. 3 star until tested Cons is not easy to distribute and the stuff lingers on you and your storage. Stinks

Like others I've used miller's before this stuff. Much better value for money with this plus I think a better effect. Makes my engine much smoother and more responsive, same with the wife's car. The economy doesn't seem massively better but still early days - I wouldn't be surprised if it does in fact pay for itself in the long run though. Anyone who claims this is snake oil (same with miller's to be fair) has probably never used it. Also, it stinks so wear gloves.

First of all being in the motor trade all of my life I’ve tried many products claiming similar benefits. I tried this product based on reviews and research and I was very pleasantly surprised when almost instantly the diesel knock and coldstart improved. I tested the emissions based on my last MOT read out and it has reduced by a notable amount. With regards to fuel consumption over approximately 2000 miles I have noticed a slight improvement I’m about 2 miles per gallon which may seem small but still an improvement. Throttle response and power has also improved so overall I would recommend using this product .