300TDi CSW Phil wrote:

I've gone through a fair few air filters over 12 years of owning the beast.

Always bought Mann or Mahle given the option.

One of the above had the outer cylinder completely fabricated from expanded metal mesh rather than a solid cylinder half perforated with holes. It seemed to last longer and work better but I only found it the once and can't find it listed anywhere.

Given it's bigger area available for cleaning air I would like to get the same type again as it did seem to improve the lung capacity of the engine.

I'm guessing I got lucky with that particular one and they are no longer available. The nearest thing I can find now it the Pipercross type of cleanable and reusable filter which has no mass obstructions between the air inlet and the filter medium.

Has anyone got any experience of these aftermarket "upgrade" air filters, do they make a difference and more importantly do they do the job properly?

MercianRover wrote:

They don't filter as effectively as a paper element - that's how they manage to flow more air. If you look at construction plant it uses paper elements, typically Donaldson as does every application where durability is key. There's an excellent comparison on an Australian website of oiled cotton gauze versus paper filters.

This is pretty in-depth but not what I was looking for:
https://www.project200.com.au/filter-testing/

If you are concerned about filter life why not fit a pre-cleaner.

Interesting video comparison that. Thanks for posting it I confess that I flip-flop between the ITG filter and paper filters depending on where my opinions fall on the subject of filtration versus air flow.

What I have noticed is that since fitting the Mantec-style downward facing cyclonic RAI head, albeit an all plastic version with upper rain gutter, the amount of water getting into the airbox has reduced to almost nothing. Whereas the Safari scoop head even with its rain channels was next to useless and regularly soaked the air box and filter. Living here in North Wales rain is something you have no choice about, if it isn't raining, it is either just about to or if you are really lucky it might have just finished

And whilst I am on the topic of air flow and precipitation... Love the snow cowl I have on Miffy as it does what it is meant to, but... in traffic it doesn't half suck up the exhaust emissions from the car in front Just an observational warning...

MercianRover wrote:

MAF isn't the critical element here, it's grit ingress into the engine and making it's way into the oil. BTCC engines probably last a season and cost is relatively not a problem.

Oily sponges are ok for dirt bikes and garden equipment, machines which are assets use paper elements.

lord-haggis wrote:

MercianRover wrote:

MAF isn't the critical element here, it's grit ingress into the engine and making it's way into the oil. BTCC engines probably last a season and cost is relatively not a problem.

Oily sponges are ok for dirt bikes and garden equipment, machines which are assets use paper elements.

That’s a fair bit of nonsense, I’ve used ITG elements for years, they are rather better made than the others. My father in law runs them on both his v8 Morgan racers that do 3-4 seasons between rebuilds.

300TDi CSW Phil wrote:

One of the above had the outer cylinder completely fabricated from expanded metal mesh rather than a solid cylinder half perforated with holes. It seemed to last longer and work better but I only found it the once and can't find it listed anywhere.

Given its bigger area available for cleaning air I would like to get the same type again as it did seem to improve the lung capacity of the engine.

I meant to reply to this earlier as I'd chased around the same issue a couple of months ago.

It's always seemed to me that the standard Defender filters 'hide away' too much of the filter material, so I was looking for a similar thing to yourself. I did find out that you need some sort of cover as this protects the filter material at the point where the air intake enters the filter housing. I posted a picture of my last 'standard' filter cartridge and it clearly shows a rusty 'blast spot' where moisture droplets come in.


Click image to enlarge

So a filter with a more exposed or unprotected paper element would risk damage, and possibly weakening at that critical spot. I found a Donaldson filter, with a plastic 'sleeve' at that point and have put that in. I think the part number is P182052. It did need the plastic fins trimming a little, but it wasn't a big deal.

(Edit: In fact it's very like the 200Tdi filter here: https://www.paddockspares.com/ntc6660-air-...WMQAvD_BwE but I don't know if this will fit in the 300 housing...?)

Does any of it make any difference at all....? Who knows. Unless you had access to a lot of high-tech diagnostic equipment it's probably very subjective. Donald

1994 Defender 300Tdi 110 SW - owned since 2002 - 230k miles and going strong
(The 'rolling restoration' or tinkering thread: http://www.defender2.net/forum/topic58538.html )
2000 Range Rover P38 4.0L V8

in the past..
RR classic - fitted with 200Tdi
1984 RR classic - V8 with ZF auto box
1993 Discovery 300Tdi

not to mention the minis and the Type 2 VW camper...