if i get a drop in box k&n filter will there be a even slightly noticable difference than the stock filter, and if so is it worth the money?

I'm wondering the same thing. I was very close to ordering one the other day on my 01 V70 but decided to get an OEM replacement instead until I get used to the car a bit. I've ran K&N on every car I've owned, this being my 12th. Are they safe in Volvo's?

Your not going to gain much Hp, 2-5 Hp at the most.

You should see slight throttlle response though.

Personally I don't think they are worth the $50, but they are a decent air filter.

A stock panel filter will be just as nice.

Only good thing about a K&N is it is washable and reusable. Over when your cleaning it and reoiling it DO NOT OVER OIL IT. Your MAF will hate you.

I've had the same K&N filter, (clean multiple times of course), in my 98 V70 T5 for the last 200,000 miles. Performance improvement negligible. Might have a little more 'growl' sound wise. But the filter has paid for itself. enough said!

+1

Anybody notice a mileage drop or improvement, or is it about the same?

It is different for everyone HummerGuy.

On my 850 I noticed a slight increase in mileage, maybe 1-2 extra miles per gallon of gas.