Hi Jay - I'm not using anything special. Just normal juice from the supermarket forecourts. Mine's an 02 VTEC but only just done 10K. My mpg has dropped off a bit lately because I've been riding it a bit harder when the weather has let me, so probably about the same as you. It picks up on longer runs though and will probably benefit from a blow out of the air filter which is an OEM type rather than K&N. I'm looking to mod the standard zorsts soon too - whip those baffles out or even cheat a bit with the 'cutting out the exit pipes' mod. Need a bit more noise from the rear end ;)