What's the journey to work like? Does the car get up to temp, is there a lot of stop start traffic... most 200+bhp petrol cars will be doing low/mid 20's in traffic and around town.
Have you tested the PCV? What gap are the plugs at, are they the correct plugs? Are the coilpacks in good condition? Is the cam follower in good condition? Are the tyres at correct pressures? Is a brake binding?