Increase in MPG/K&N

[fazersharp]

You still don't believe me do you?  [img alt=:lol]http://foc-u.co.uk/Smileys/efocicon/lol.gif[/img]

No and neither does Fazerider

I agree, it's psychological (assuming that's what you meant). A filter that is less restrictive won't alter the fuel/air ratio and the amount of work the engine has to do to pull air through the filter is trivial. It will make a difference at the top end of the engine's performance where it will make a couple of extra horsepower available (with a corresponding increase in fuel consumption).
I neglected the air filter on my bike for many years, it probably did about 80,000 miles in that time. There was no detectable change in mpg when I put the new one in.

I think the OEM one will be the last one I buy for the bike 16000 miles over 15 rears till first change so my next will be at 32000 miles in the year 2029