Thanks all for the replies i really appreciate the info.

Im gonna go and do the MPG game has some have suggested i toyed with it a bit today and i got 20 WOW all LA stop and go of course but still. For those that are wondering im Using high quality (chevron) 89 octane i have heard that shell is the best but i dont think it should be giving me a 5-7mpg difference on the next fillup i do need to calculate via calculater and not OBC but i do trust it idk

 

rob490, One other thought, I used to get poor milage from my MINI until I noticed that the pattern was random and always occurred when I filled up at a certain (name brand) station. On one occasion I filled 14.6 gallons - in a 13.1 gallon Clubman tank. This station/pump was over stating the volume and thus over pricing the fuel. My milage, divided by the bigger gallon number gave a lower avg. milage.
You said you (always?) use Chevron and if it is always at the same station you might verify the numbers with a fill at the newest other station you can find. The new station is more likely to have recently certified pumps.