My dads mate who replaced the headgasket said to run it that much. runs cooler?!?!? Its had a stage 2 upgrade and boosts at 16psi. i have noticed that since its been set at that mixture as u pull away and the revs are quite low it does bog down alot but pulls really hard higher up the revs as the turbo winds in (but thats set by ecu isnt it?!?) its CRAP on fuel since the rebuild too its terrible! So it should be ok to set it at bout 2.0%???