PDA

View Full Version : Don't trust your mileage computer


330 Sport
08-11-2008, 11:25 AM
(EDIT: Disregard the screen name - I recently upgraded to a 2005 645ci.)


Many a time is it that I've pulled into a gas station with only fumes in the tank - according to the "miles until empty" reading on the dash computer.

Of course, I would then fill up only to find that I still had 2-3 gallons left in the tank. I always assumed that Deutschland skewed this data to err on the side of caution.

Well, I became painfully aware that this was indeed NOT the case on a recent trip thru the Cherokee mountains in North Carolina. For those of you who have not been on this road, it is a beautiful, dangerous, scenic, dangerous part of I-40 with many twisties, elevation changes, tunnels, and jersey barriers (read: little or no shoulder on the road).

It's a nice day, sunny and warm. I'm getting a fantastic 29mpg as I cruise to my destination of South Carolina. *CHIME* goes the car - a big yellow gas pump icon appears on the display. OK - getting low on gas. Miles til empty - 70.

Since you can find more radio stations than gas stations in this area (there's one radio station), I figured I'd be just fine getting thru the mountains before stopping for gas. Wrong.

With the trip computer showing 30 miles til empty, my 645 died, dead as a dead doornail. I made it over to what passed for the shoulder of the road and sat there in disbelief. Out of gas? OUT OF GAS?!!

So there I'm on the side of a mountain as semi's whiz by. I call road service and they ask me where I am. I can see no road signs, no exit signs, no mileage markers. The best I can do is tell them my long. and lat. on the GPS. Not much help.

An hour later, the surly tow truck driver finally arrived and spilled about 3 gallons of gas down the side of my car; some of it getting into the gas tank.

*****

On the trip back from SC, I stopped for gas shortly after the low gas warning icon lit up - the car took 15 gallons. I had 3.5 gallons in the tank.

If they can send a man to the moon, why cant they ...??

superdopefresh
08-11-2008, 11:34 AM
that's strange.. i actually drove about 15 miles once when my car was saying 0 miles left. not a good idea but i didn't have my wallet on me at the time and had to make it home. that sucks that you got stuck up on the mountain but on the bright side, you got a tow truck to show up in just an hour? that's pretty fast considering your location.

btw, i have 2005 645ci as well.

Stratus650
08-11-2008, 12:10 PM
Glad you made it safely, I think it's time for a software update :p

330 Sport
08-11-2008, 02:53 PM
Doubt if it will do any good...

Lucardes
08-11-2008, 04:46 PM
Doubt if it will do any good...

Worth the try, because that milage issue on gas I never received that issue so it is very remote....It could be because you were going uphill and the gas level looked like more than it had, not exactly sure. But I know definitly my gas milage is fine and other friends that have the 6er. But it could be that going uphill it fools your gas sensor.

ohitisethan
08-11-2008, 09:23 PM
i think the reason why was because your car was at a certain angle where the gas tank gets tilted and the car cant remove the gas out of the tank thats y when u go up a large mountain u need alot of gas with you

JD650
08-11-2008, 11:20 PM
i think the reason why was because your car was at a certain angle where the gas tank gets tilted and the car cant remove the gas out of the tank thats y when u go up a large mountain u need alot of gas with you

I second that .....