Yes and not really!

Less service cost in the long run?

I was really hoping you were seeing improved economy and throttle response therefore justifying my purchase.

Well - there are so many variables and I'd be less than honest to claim a benefit at this stage! TBH, I fitted it and had forgotten all about it!

There doesn't seem to be any increase in induction noise though

I've noted when I fitted it and will keep an eye on fuel consumption etc., but I'm not really envisaging a massive improvement!

None of the manufacturer's claims are quantifiable - other than longevity IMHO

Less service cost in the long run?

How much was the K&N filter, cleaning fluid and oil?

How much is an OE filter?

K & N filter £34 Oil/cleaning kit £10 = 50k+ miles

OE filter £17 from dealer = 20k miles

How long is a pice of string?

Wow that is much cheaper than I have seen them (IIRC they were around £45?)

The single biggest reason I have not entertained was because of the cost and cleaning hassle (compared to just chucking a new one in), I know Skoda reckon they don't need changing for 60K miles!!! but personally mine will be done at every variable service.

I have no doubt that a K&N can flow more air than an OE paper filter, but the OE flows more than enough so I am not interested in one for 'performance gains'

I think I'll be giving one a go, from previous experience I think they are good quality certainly better than the standard.

+1 Agreed.

Resurrecting an old thread... My k&n has been in for a few thousand miles now and I'm convinced it DOES seem to have improved my fuel consumption. On a regular known run I'm seeing improvements of 4mpg ie 33mpg instead of 29mpg and when it's being pushed harder, the fuel economy drops less than when running the paper filter (with 9,000 miles on). I believe these improvements are down to the filter swap and I feel pretty sure that a new paper filter wouldn't have given the same increases. If I can be bothered I guess the best way to confirm would be to swap back to the paper filter for a few hundred or so miles...

Further to my post above. Ive used the car daily this week for my weekly commute (normally I use our Fiesta 1,6 TDCI). Ive never had economy like it from the Yeti! I have been driving sensibly but the route is 10 miles dead consisting of 50% A road and 50% stop start town traffic. The calculations are taken straight off the maxidot display. While I appreciate this isnt the accurate method, im simply after a baseline for comparison. Previously, Id expect to get around 32mpg on summer tyres and Shell V power (which is what it gets at every fill up).

So this week, wIth the K&N panel filter in place I have achieved:

Mon - 38.1 mpg

Tue - 37.1 mpg

Wed - 37.9 mpg

Thur - 38.3 mpg

Tonight I'll be swapping the K&N for the OE paper element.

I changed my OE filter for another OE one last week, I've done 13000 miles and looking at the one that came out there's no way I would leave it for 60000kms or 4 years.

I changed my OE filter for another OE one last week, I've done 13000 miles and looking at the one that came out there's no way I would leave it for 60000kms or 4 years.

Totally agree. My paper one would get an annual change and with the k&n I'm thinking of a clean every two years max unless they recommend more often.

I changed my OE filter for another OE one last week, I've done 13000 miles and looking at the one that came out there's no way I would leave it for 60000kms or 4 years.

Totally agree. My paper one would get an annual change and with the k&n I'm thinking of a clean every two years max unless they recommend more often.

To clean or not to clean; that is the question!

Instructions from K&N suggest that you can fit and forget for 50,000 miles. OE paper filters are to be changed at 4yrs/40,000 miles IIRC but if you have a look at the dust & debris that has been held by the filter you want to change/clean it at around 10,000 miles.

I used to run K&N (or similar) filters and would religiously clean then around every 5 - 7,000 miles and I felt happy knowing that I had a clean filter.

However, I've currently got an ITG 3 layer foam filter (similar to Pipercross) and their instructions are 'fit & forget & the dirtier it gets the better it works'. I had it in my Octavia vRS for around 15,000 miles and have now had it in Yeti for 19,000; total 34,000; without touching it apart from a periodic check to pull any large debris i.e. leaves, off it. Its looking really quite dirty but is it doing any better or worse job than a clean or dirty K & N? Who knows?

Shall I replace it with another ITG or switch to K&N? Another important decision to make.

Years ago when doing courses at the Royal School of Military Engineering in Chatham, an old instructor used to say, "think of an engine like your body,eg breathing = air

food=fuel

blood=oil

What he was basically saying, and which makes a lot of sense is, fill it full of CRAP and it don't work so good. I've always remembered this when servicing my cars ever since.

Right, the results are in....

Previously, with the K&N filter in place Id seen the following results...

Mon - 38.1 mpg

Tue - 37.1 mpg

Wed - 37.9 mpg

Thur - 38.3 mpg

Fri - no result.

Over the course of this week, with the standard OE paper filter back in place Ive seen:

Mon - 32.1 mpg

Tue - 33.6 mpg

Wed - 33.1 mpg

Thur - 32.3 mpg

Fri - 31.2 mpg

By no means conclusive but Im pretty amazed and as you can clearly see from my earliest comments on this thread - VERY surprised to see these gains! Ive tried to keep the driving style similar, changing up when indicated. Its a commuting route Ive been doing for 13 years this August, so I know it well. For the above results its been done at the same time each morning (6.30am) during a two week period where traffic count and ambient temperatures were similar.

A couple of further observations... my car is mapped for better fuel. I believe this may have something to do with the gains I see as the standard filter would surely be more of a limiting factor on a mapped engine? Having said that, the OP of this thread is running a standard car!

When you do 'push on' in my car, I seem to suffer a bigger mpg loss on the standard OE paper filter compared to when the K&N is in place. Im surprised by this but Im certain this is an accurate observation. Also, sitting at higher speeds, cruising last weekend definetly showed the same reduced mpg with the paper filter over the K&N doing the same run the previous weekend.

Right, the results are in....

OK; that does it for me. Convinced that a K & N, or similar is the way to go (although I've been using them for years already ).

As I have perhaps previously mentioned I have an ITG foam filter in place at present which, as it is coming up for 35,000 miles 'old' I'm thinking of replacing. I've had K & Ns before and been quite happy but have been reading up on Green Cotton Filters, which are very similar but boast a larger surface area due to 'deeper pleats'.

Anyone have experience of Green Cotton Filters at all?

Having said that, the OP of this thread is running a standard car!

Errrr noooo

It is a Shark remapped CR110 2wd......pushing out about 170bhp :lol:

That reminds me of my old Triumph Spitfire Mk3.

I replaced the engine, just a straight swap complete with gearbox, and the replacement had 11/2" SU carbs with a gauze & foam chrome air filter. Under load would not rev over 4000rpm. Spent ages trying to work out what problem was. Car had 4-2-1-2 exhaust fitted as well. Original engine had 1 1/4" SU carbs fitted.

In the end I put the standard airbox & filter from the old engine on and all problems disappeared. Too much air and not enough fuel.

The Spitfire was fantastic after that. Had a few handling & brake mods as well. Handled like no other mk3. Actually handled as well as a MK iv Spitfire.

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I had a 1973 Mk IV Spitfire with gauze filters and I got exceptional performance by gas flowing the carbs and reducing the needle sizes.

Went like stink after that!