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What be the impact of replacing my current (stock) airfilter with a K&N one?
Website cites an increase in fuel economy, is this really the case?
Not really interested in a marginal increase in power but definitely interested if its going to increase fuel economy.
Car is a 2.5l Subaru Outback.
Ta
No chance
It should last longer though
+1.
Its not really worth it IMO.
A better way to improve mpg would be to check your tyre pressures regularly, stick injector cleaner into your petrol, change the oil/filter twice a year etc etc. Then you'd probably end up spending the extra ££ to get better mpg and the benefits would be cancelled out by the cost.
NICE car though 😀 How long have you had it, what year/mileage etc? Is it an auto or manual?
Had it for about 18 months, 2004 model, 35k on the clock, manual, leather.
Great car - I'd just like to eke a bit more than 34mpg out of it!
What VED is it annually?
35k in 6yrs!?!!!! 😯
I might be interested when you come to sell on.
34mpg isn't that bad for the amount of car you get for the money IMO. You could buy a VW/Audi/Seat/Skoda 1.9TDI for probably more money but less of a car alround IMO. You'd probably save c£600 a year in fuel but is it that important?
If you're talking about the normal ones [non induction] then it's just an air filter. If you have a classic car that you are likely to hold on to for years then it's worth it as all you do is clean it every year. On modern cars that you normally get rid of every few years it's not really worth it considering filters are between £5-8 from most motor factors.
An induction kit may increase bhp but doesn't necessarily improve fuel consumption. You can get your engine remapped to increase fuel consumption but then your performance will/may reduce.
Looking at Parkers they are saying about 32mpg so don't think what you're getting is too bad. As said above a good service does wonders for your car.
Doyou do oil changes befre te recommended service intervals? In my old 306 I used to service it every 4k [oil, oil filter] with a main service every 8k[all filters and oil]. Was getting much better fuel consumption from that than my mates were getting from theirs.
As said above your best bet is
I have one in our xc90 but only as a direct replacement for the paper one. I got it as it was a good price and should last the life of the car so over all will cost me less. I don't know of it has improved the economy but it hasn't made it worst.
No real point in putting a K&N on a normal road car when the filter is designed to supply enough air for the horse power it produces as standard.
If on the other hand it has a high lift cam, twin 45's DCOE's a decent gas flowed head and a good exhaust system then the sound is nothing short of magical!
Be careful. From my Subaru days they were known for the oil coming out of the filter and breaking the MAFs
ITG panel filters were the ones to use
MM
Oh, I really do miss my Foz 🙁
On the race bike yes it makes a difference. But that is 760BHP per tonne and designed for maximum power and high revving etc.
In the car it's no difference and not worth the cost when I can buy 8 regular type for the same price.
If you were bothered by economy, you wouldn't have bought a 2.5 4x4...
Doesn't make a difference, as new the OE paper filters give better air flow and more power/torque/economy. But the paper filters clog up sooner than the equivalent K&N type filters, which to my mind means they probably allow more rubbish through in the first place. The one big saving grace of the reusable filters is the fact you can reuse them - less landfill, but still need cleaning every 6k miles or so.
My comments are based on a magazine test I saw some years ago. Things might have changed since then.
If you were bothered by economy, you wouldn't have bought a 2.5 4x4...
Fair point.
Waste of money on a standard road car as stated above.
I use them, but only on the twin 40's 8)
I had an HKS filter in my old Scooby WRX, utter loveliness. Since then it's been sad normal cars for me 🙁
I have however used K+N panel filters in a few previous cars and have put one in my current car Pug 307 HDi but mainly due to habit and the airbox is really really annoying to get to. Not had any problems with it but also not really noticed much differnce with it.
Personal choice really.
They look SWEET!. I had K&N's for a while, on my 125cc motorbike and on my mini. And that's where they belong.
If you were bothered by economy, you wouldn't have bought a 2.5 4x4...
Fair point indeed.
However, if the answer to my first post had been a resounding "Oh yes, they make a huge difference" then it would make sense to change the filter.
It would appear that there is no point though.
Hora - £215 a year.
A better way to improve mpg would be to... *snip*
Duh... he could do those things AS WELL as changing the air filter could he not?
Classic STW question mis-understanding then. Not asking how to improve his mpg, he's asking if K+N air filters make a difference.
Taff, I fail to see how changing the oil more frequently would help fuel economy significantly. However subtle differences in driving style and the exact roads you travel on can make a pretty big difference. So I'd suggest that'd be the first place you should look as to you two people with the same car get different MPG.
MPG, no difference, power, no, forget it.
I've fitted K&N filters to cars where I've had emission problems (think mildly smoky diesels) and found that they help in that situation.
Wouldn't really call an Outback a 4x4, it has a 4wd system, but it barely rates as a hairdresser/softroader in reality.
Depends how restrictive the old or std one is.
I personally would just change the filter for a bog std one each yr or how many miles needed for servicing.
If the old one is old, clogged and needed changing miles/yrs ago then sure it will use more fuel but not loads.