i get anywhere from 288 - 310 per tank when the light comes on. Which I havn't recieved worse then 25.7mpg if I recall correctly. I do pump premiem into the p5. I seem to have a bit more power vs useing reg grade gas. I.E. i can floor it with reg gas from a stop and can't spin the tires but with premiem i can. (this does happen on my p5)