that 0.5 hr seems to make sense because after i gas up, my gauge doesn't reflect the new gas level until after about 20 - 30 min later.[/QUOTE]
That is actually a gas gauge problem. There are some post about it. If this happens to you after filling up your car, then it can be corrected by having the gas gage re-calibrated. (Just another Porsche Boxster flaw) Otherwise it's just more of a neuwsence than anything else. Gas gauge needle should rise to full tank after you fill it up emidiately after you turn the ignition key.
