2012 BMW X3: Zero Range and Too Much Gas
April 18, 2012
Yesterday in the interest of research I drove our X3 until its trip computer said it was out of fuel range. At 56 miles to go, the car began to tell me to stop for fuel, but it continued to count down the range as I drove. And it counted all the way down...5,4,3,2,1 and then the ---- you see on the instrument cluster in the photo above.
At that moment I immediately pulled into a gas station and filled the BMW's tank. That's when things got wierd.
It took 17.979 gallons of 91. Now according to BMW the X3 has a 17.7 gallon tank. So I scratched my head and checked the X3's fuel log. Sure enough it had taken more than 17 gallons more than a few times. Didn't seem right. So I emailed BMW for an explanation. Honestly, I thought the response was going to be something like, "Oops we screwed up. the tank is really 19.7 gallons. Sorry about that."
Instead the response was, "There are a lot of potential explanations. One could be manufacturing tolerances. It's possible that the tank in the X3 you guys are driving is slightly larger than the indicated 17.7 gallons, based on manufacturing tolerances. It's possible that the amount of fuel that comes up the fill tube varies from fill-to-fill. I've been told that fuel volume as indicated on the pump is taken at a benchmark ambient temperature for calibration purposes so if you are putting fuel in the tank below that benchmark threshold, you're actually getting less fuel per indicated gallon than you think, so it could look like you are putting more fuel in the tank."
This is a strange one. I put gas in dozens and dozens of cars a year. Seems unusual to me that BMW's manufacturing tolerances would vary as radically as to add atleast a gallon or three to the size of its gas tank. Also, considering we're in Los Angeles, which isn't really known for its temperature swings, I'm not sure I'm buying that either.
The fill tube seems plausible I guess, but just as unlikely. Again, I've never run into this before. Have any of you?
Scott Oldham, Editor in Chief