This might be a really strange question, but have Mountune ever manufactured a WHITE high performance air filter for the mk3 focus? I have a white one in my car at the moment and it is a genuine Mountune. I just wasn't sure if it was so old that the colour had faded and it needs cleaning and oiling. All the Mountune filters I see being sold are red Like K&N

Is Mountune written on in biro?

Mountune filters are red now because they're made by K&N.  

They used to be made by Green Cotton.

I'm not aware of any white filters though.

Ah, fair enough. It does have Mountune printed on it along with a number. After work I shall take it off and get some pictures. Looks like I've got a special edition, one of a kind 😆

I’ve had a look. I feel incredibly stupid. After looking into it, it looks likes like whoever owned the filter before me had cleaned it, but not re-oiled it as there is a very slight tinge of red in the fabric still. I’ll have to pick up a can of K&N Air Filter Oil spray tomorrow. I’ve given it a good clean now anyway. 
 

before anyone says, no, it’s not a dry filter ☺️👍🏻

Take care not to over-oil it to prevent coating the MAF.

(I know K&N say their oil doesn't affect MAF's, but they might have a vested interest in flogging more oiled air filters. )

Thanks for the advice 👍🏻. I’ve just ordered some K&N oil spray, washed, cleaned and thoroughly dried the filter ready to be sprayed and put back on the car.
 

I’ve had to stick a standard clean air filter on for now. It’s quite surprising how much of a difference it makes, in noise and performance. 

10 hours ago, Pburgess2208 said:

I’ve had to stick a standard clean air filter on for now. It’s quite surprising how much of a difference it makes, in noise and performance. 

It shouldn't be.  Many years ago I had a set of dyno tests proving that performance air filters don't make a difference to performance.

The difference is just noise, which gives the placebo effect of improved performance.  (Or at least was back then).

I tried K&N and Pipercross on cars in the past, but as I used them to replace very dirty OEM items, I never figured out if they were of any benefit compared to a new standard one.

I was considering trying a Mountune on my current car out of curiosity/for old times sake/whatever, but as they seem to be permanently out of stock..........

I have seen reviews of products by the following which seem very similar to Mountune stuff:

https://09design.com/

On 12/6/2025 at 9:17 AM, TomsFocus said:

It shouldn't be.  Many years ago I had a set of dyno tests proving that performance air filters don't make a difference to performance.

The difference is just noise, which gives the placebo effect of improved performance.  (Or at least was back then).

After trying both a stock and the mountune, I can certainly feel a difference. Certainly when the turbo starts sucking in more air. The filter that I have is open ended so theres definitely more air being sucked in, whereas with the stock, its closed ended and the filter material is more dense. Built for maximum filtration and not performance.

On 12/6/2025 at 5:09 PM, Eric Bloodaxe said:

I tried K&N and Pipercross on cars in the past, but as I used them to replace very dirty OEM items, I never figured out if they were of any benefit compared to a new standard one.

I was considering trying a Mountune on my current car out of curiosity/for old times sake/whatever, but as they seem to be permanently out of stock..........

I have seen reviews of products by the following which seem very similar to Mountune stuff:

https://09design.com/

I was the same as you, I wanted to try a performance filter to see if there were any performance improvements, but the good filters were too costly to justify getting one. I bought mine second hand from facebook market place. Hence my initial question ☺️. I thought i had been scammed, but it turns out that the filter I bough just needed cleaning and re-oiling. It looks as good as new, now its been oiled. I bought a Mountune, it has the part number and logo imprinted on the rubber ends and it was in a Mountune box.

After trying both OEM and the performance filter, I can notice a subtle difference in acceleration, but nothing ground breaking. There is also a slight improvement in the sound, especially coupled with an RS Style air box. I'm glad I just went for a cheap second hand filter though rather than paying full price. I think i would have been very disappointed.

1 hour ago, Pburgess2208 said:

After trying both a stock and the mountune, I can certainly feel a difference. Certainly when the turbo starts sucking in more air. The filter that I have is open ended so theres definitely more air being sucked in, whereas with the stock, its closed ended and the filter material is more dense. Built for maximum filtration and not performance.

Well, if you can prove that with a pair of back to back dyno runs then I'll believe it.  

The same air filter and box was used on the 2.0 turbo ST.  It would be impossible for your 1.6 turbo to be pulling more air than that.

5 minutes ago, TomsFocus said:

Well, if you can prove that with a pair of back to back dyno runs then I'll believe it.  

Believe me, If I had the money to spare, I certainly would. I'm very intrigued to know myself ☺️