Nitrogen versus air

So I've had my Focus for 3 years + and about 44k miles. A few track days- I feel i know thee car pretty well.

Until the most recent set of tires...

Source: http://www.motorsportforums.com/forums//showthread.php?t=140236&goto=newpost

Bo Granath Mick Grant Silvio Grassetti Simone Grotzkij Herve Guilleux