K&N 57S-4000 Washable and Reusable Car Performance Intake Kit

Installed this on my 1.6 ecoboost Focus about 6 months ago (removed the rubber bung from the end) - Noticed a slight improvement in torque as the car is more eager under acceleration. There is also a very small increase in induction noise, but as others have mentioned you do get an increase in turbo whistle and a louder sound from the stock bypass valve. However unlike my other cars that have had K&Ns fitted, I haven't noticed any improvement in mpg.All in all a very nice filter and very easy to install - just make sure you don't drop the airbox lid screws!

bought this recently to add to my MK3 163PS, after it had it Bluefin remap done. replacing an existing K&N E-2993 filter.what a difference, beautiful noise and with the centre rubber gromit removed, the car can draw in as much air as it likes. saves you money each service too, no more paper filters.easy to fit in 10 mins or so, remove top of airbox lid (store safely) take screws off and fit new filter, use new K&N lid and existing screws (don't over tighten them). if you haven't opened the airbox before, it may take a bit of effort to break the air seal, so watch your knuckles and nails!! easy to look after about once per year take it out and clean with the K&N recharge kit.

Did what it said on the box well worth the money will definitely buy another

The boy racer in me is still alive and I thought this would make a nice addition to the engine compartment of my Ford Focus 1.6 182 estate. Judging the product by previous reviews I thought that even if it doesn't increase the bhp at least I might get an extra snarl when I accelerate.I used to love the sound of my twin webber carbs topped with K&N's sucking in the air and popping as I accelerated on my old Alfasud Ti and Sprint Veloce.It arrived without extra packaging in its own box. Opening the box I found an instruction booklet, a filter sealed in plastic and a plastic air box lid. There was also a rubber bung and some paperwork that stated it had passed TUV testing on the continent.It was simple to install, undo the top cover of the air box by undoing x4, 7mm hex top screw in bolts, jiggle the lid of the air box and remove. Slide out the original paper filter by pulling it out towards the right. Keep the screw bolts to hand.Push the K&N into place, put the new top cover on and screw down. So long as it is lined up there is no need for bending and straightening the plastic top cover. It fits like a glove. Using the screw down bolts you kept to one side earlier, fasten the cover down.Word of advice, one or two of the bolts are fiddly and recessed in narrow gaps so take care you don't lose them.It took me all of 7 minutes to have everything in place. If it takes you longer than that you are doing it wrong.So the big question is, does it give more BHP, more torque and sound like a formula one engine?I took my car for a Sunday morning, no traffic on the road, kids in the back going to swimming lessons test drive.First impressions are that at low speed, the acceleration feels a little more eager and lighter. At 30 mph touching the accelerator lightly and coming off again gives a slight but deeper exhaust rumble. Once on the bypass slip road, giving the car a good boot, it did seem more eager and more instantaneous in acceleration. Whether it was quicker or not I can't say but the engine seemed to respond quicker.The sound was no different than before inside the car with the windows closed, though the sound symposia that channels the 'roar' into the car was an octave or so different. Definitely not louder though. In the cruise at 70mph it was as quiet in the cabin as usual.There was too much wind noise with the windows open to notice a difference from the outside.Whether it is psychological or not there is more eagerness in acceleration and pulling away and it does feel faster. As to the 'snarly roar' I was expecting it didn't live up to the twin Webbers and Ansa exhaust system of my old Alfasud but here is a change in sound though nowhere near what I was expecting. Fuel consumption remains the same.My only gripe is that the Filter Kit is expensive for what you get and that is the reason I waver between 3-4 stars.

Got kit as an Amazon wearhouse deal, so used, but no issues (a little extra dirt can be an advantage with this type of filter 😉).Noticeable improvement in throttle response and low-mid range pick on 1.6 ecoboost focus with a remap. A little disappointed with just the map, quicker, but also quieter than the standard set up as the extra turbo noise defeats the sound symposer on my model and makes for near silent running. This filter makes the most of the remap, and with the bung removed, brings the noise back as well.I was sceptical about the power gains having tried aftermarket filters in the past, but this definitely makes a surprising difference. Worth noting ford use the same airbox and filter assembly across the focus range, except the st, which gets a secondary inlet to the airbox, hinting the stock set up is limiting when pushing 200bhp. So I expect it is the ability to create the extra intake with the bung removed that helps bring the performance gain.Fitting is also very easy, in fact the filter is a much better fit than the stock paper filter, which needs to be squeezed into the air box base.I tend not to run the k&n all the time as it does filter less well (but that's the point!) and I don't need the extra grunt on my daily commute to work. But fun for the weekend and mugging 320d drivers when the occasion allows.

Sounds great on my focus ecoboost. Fitting was easy just screwed top from left to right fits lovely. Has a nice hiss noise when u accelarate. Filter has been on for a month now and has been working great.

a really simple and quick fix to the car; undo four bolts, lift off old airbox cover, remove old paperfilter and reverse fit the new items c/w the new airbox lid. I haven't run the engine without the 'rubber bung' yet, but I can notice the subtle difference in the way the engine pulls from low RPM and spins when pressed. It'll be interesting to monitor fuel performance too, but over short(ish) distances so far, its behaving itself. I cant quite believe that quite a simple (relatively) product can make that a difference that I can genuinely notice. The price is a little off-putting, but overall im impressed.

Product wasn't as described, sent out the wrong filter completely. Returned.