Chip for a H2

has anyopne chipped there H2 if so please respond with cost and what kind or if anyone know which is a good one and how much did it increase MPG

i used the hypertech programmer, primarily for the change in tire size. i did change it to 93 octane performance upgrade, noticed a bit of improvement, but mileage still blows. if anything, my mileage is worse than stock programming with stock tires. but the shifts are tighter and the speedo is accurate.