Help: extremely poor gas mileage

[Werewolf]

Hi all

I own a 2001 3.0i with a manual tranny. Recently, last week or so, I've been experiencing extremely poor gas mileage (8 in city and 15 on freeway or less). My driving style is no different than before nor are the distances or types of driving.

When I drive for short trips (5 miles or less), I notice the gas gauge drop visually. Even 20-30 mile trips are taking 1/8 to 1/16th of the tank. None of the engine lights have come on. I have checked for fuel leaks and vapor smell and can detect nothing.

The only thing I can think of is I changed the oil on the x5 and did not reset the maintenance interval so I am on orange-red (instead of the green bars). Would this effect mileage? (i.e. adjust fuel-air mix?)

Thanks in advance