Increasing Power On A 1.8Vvti?

[hora]

Ok, lay my cards out here. I'm not after a 'Maxpower' powerhike etc.

Would the likes of a K&N air filter help noticeably?

Any other subtle changes that you have found work for you?

[Thermal]

Would the likes of a K&N air filter help noticeably?

No, I don't think so.

The only thing that would substantially increase performance of any petrol engine is the addition of a (turbo-) compressor.

If you really want to know, put the car on a Dyno, before and after fitting that air filter.

And even if you would gain, say, 5 Bhp, which I doubt, you probably wouldn't notice.

It may look impressive, and change the sound, but that's all.

The same goes for plastic skirts, spoilers, and oversized alloys.