Wynn's Extreme Diesel System Cleaner - Deep Cleaning Engine Treatment - Restores Fuel Economy & Reduces Emissions - Prevents Turbo, EGR Valve & DPF Issues - 325ml

I was quite sceptical of just how effective a small bottle of Diesel cleaner could be with used with my 11 year old vehicle. My diesel car has been used mainly for very short journeys over a period of several years, so has suffered the usual DPF and EGR issues that are expected when you don't properly take a diesel vehicle for longer/hi-revving journeys. My situation has now changed with a new job and I have to travel about 30 miles each way to work and back - I immediately noticed that the car had become extremely sluggish and really did not want to rev easily when trying to match the speed of an adjoining main road. The DPF and EGR had previously been cleaned by a local garage but given I live in quite a remote location I had not has need to drive on an 'open road - motorway etc' to be able to maintain a decent speed in order to maintain the cleaned components. (Also, the current cost of Diesel really encourages super-efficient driving). Now that I need to travel further to work, the car was not happy to rev beyond 2000RPM which made progress and acceleration very slow. Hills were a nightmare and the car really felt like something was severely holding it back (I thought something mechanical was wrong with it, even though no lights were showing on the dash). I read that Wynn's products were supposed to be good at cleaning out fuel and exhaust systems - so decided to give the Extreme Diesel System Cleaner Treatment a go before booking the car back into the garage. I added the whole bottle of treatment to about 40ltr of diesel, having ran the tank low and pouring the treatment first before fuelling up - to help with mixing in the tank. I was very sceptical, but I thought that for a few quid over a possible several hundred for garage diagnosis/repair that I'd give it a go. For the first 50 miles, not a lot changed - but during driving the car along a long stretch of the A1(M) the engine really seemed to clear its throat and suddenly seemed to be able to rev up a lot more easily. I didn't really notice until nearing my destination where I had to filter onto a roundabout and accelerate up to speed. The engine revved much quicker and could probably have reached the red-line. Acceleration was much improved and over the next 50 to 100 miles the vehicle has become far more responsive. I have noticed a genuine economy increase of 6 to 8 MPG with much better engine performance. I'm not making this up or sponsored or anything like that! Just trying to be helpful in my review. I appreciate that my circumstances may be unique in that my car was probably fairly coked up and not able to complete a powerful combustion process, but adding Wynn's Extreme Diesel System Cleaner really does seem to have had a positive impact on my engine performance and fuel economy. For reference, my vehicle is a Mitsubishi Outlander with a 2.2D Diesel engine which now produces 56MPG on a 30 mile commute each way (driven at 60mph with moderate acceleration as required). I hope this review is useful. If your diesel engine is lacking in performance and mechanically sound - maybe give Wynn's Treatment a go, it certainly does seem to have had a positive effect on my vehicle and I feel that it has saved me potentially spending a lot of money on professional garage services to bring the performance back in to check.

Really pleased in this . Does what it says . Difference in performance is good too Keeps car running great ..Recommend this. Will buy again when need more ..

Used on a 20 y/o diesel that had moderate injector blockage, shuddered moderately when foot fully down on pedal. The advice for this says once every few thousand miles but I ended up doing two full tanks back to back with shell fuel, and that did reduce most of the really bad shuddering. It has however not completely removed it all. Perhaps the blockage is really bad and so ill give the bottle of Wynn the benefit of the doubt that its done as best as it can. It is a bit pricier than RedX, which is £5 for 2 dosages at the local supermarket, compared to this, which is only 1 shot.

My older 1998 T4 2.5 was starting to struggle up hills, and felt a little different to her normal running. Let her fuel (diesel) run down to 1/4 tank and added two bottles into her tank Drove about for about 20 miles and saw my revs able to increase and pulling up the hills in 4th instead of 2nd. Almost feels like I could use a 6 &7th gear lol After the 20 miles I as usual put £20 (10L) of premium diesel in as she runs like cr*p on standard diesel and feels like a new van. Now when we visit Cornwall and its hills we know it won’t struggle on the Barnstaple bypass hills and will be as good as she was years ago. Using this before I forgot how good it is so will be using once a month for maintenance purposes as clearly it removes the hesitation and cleans where the premium diesel doesn’t.

Works well

Excellent system cleaner that increases my FL2 MPG to 34. It feels smoother, runs a little quieter, and is more efficient. I've used STP and it works in a similar way, but I switched to this a few years ago and have stuck to it.

Bought this based on the reviews, but in all honestly did it make a difference? No idea car drives the same as it did before, not that I had a problem, it was added more on a preventive bases.

I had an EGR valve stuck in the closed position on a 2013 320d. I was fully expecting it to be a new egr or at the very least a break down and manual scrub situation but one bottle of this stuff in half a tank of regular diesel and a 20 minute drive at 2000 revs and the engine warning light has gone.