Any filter that requires oiling is not a good idea, at least on road cars. The whole idea of sports airfilters is to allow a free air flow. Oiled filters work reasonably well when clean, and freshly oiled to the correct degree using the correct oil, but the oil catches the dirt (as it should) and they quickly loose efficiency. Fine if you are racing and clean and prepare it before every race meeting but not so good on the open road.
There are several types of high flow airfilters that use cleanable elements, usually washeable in warm soapy water, that are much better suited to road use.
I have no idea what is available in the UK.
The better type of road filters such as K and N ITG, Green, BMC are generally all foam filters which need an oil based spray to enhance their performance to to the maximum.
I'm not taking about oil bath filters here but as I said, foam filters which need a light oiling or spraying ( I'm not even going to mention paper element filters as their shortcomings are well documented) All research shows they are infinitely preferable to paper elements and indeed cotton
It is also the case that such filters should be washed a re-oiled at appropriate intervals
One last point if I may, the whole idea of a filter is to allow CLEAN air flow. I know this is further back than many TMers will remember, but anyone who can recall what running without air filters did to the heads of the works Hillman IMPs in the 60s and 70s will never forget that lesson!
G
