The fuel gauge on my 2007 Cooper seems to be out of touch with the actual contents of the tank. When 5 segments of the gauge are dark (indicating 1/2 tank remaining, I assume), I can put in 9.5 to 10 gallons. The tank is supposed to hold 12.5 gallons, so either the gauge is wrong, or the tank holds 20 gallons. Anybody noticed the same thing? Apologies if this has been posted before -- I couldn't find it...

 

The last two segments are for reserve (they change to red). Not sure if it changes your estimate. I haven't tried filling up with half indicated. Will do next time and see if I have similar results. Last time when I hit reserve, or 2 segments left, it took 11.994 gallons (no topping off). I only drove about 3 miles once reserve.

 

I've put in 13 gallons with one red bar showing and 60 miles to empty on the OBC.
The actual contents of the tank have been tested by a few unlucky members.
My advice is to be wary and err on the side of caution. Especially when you're near vast wastelands like Nevada, etc.

 

I've noticed that the gas guage seems to exhibit the same behaviors as the gas gauges in the two BMWs I've owned previously: it'll take quite awhile for it to show even one candy corn gone, and a similarly long time for the second and third. But once you get past half the candy gone, they disappear at an increasing rate. It's definitely not a linear projection.

According to the manual, it figures out the range number from how much gas it thinks is left in the tank and your average mpg for the last 18 miles. So if you've been doing a lot of highway driving, but then switch to a situation w/ a lot of stop 'n' go it's going to be rather off for a bit.

 

Thanks for all of your inputs! I'll do some more experimenting and mention the issue to the dealer when I go in next month with a list of warranty fixes. It's probably true that the Mini fuel gauge is too smart for it's own good, just like a lot of the other electronic stuff on cars nowadays...

 

I don't think there's anything uniquely 'wrong' on your car

my gas gauge is also 'non-linear' - 07'S

I'll typically have 120 to 150 miles on a tank before the first 'tic ... then they go out progressively faster....

I can live with it, but no 1/2 indicated on the scale is not 1/2 tank left....

Much farther off than my 02 was.... actually close to the 79

 

Exactly. It's more than likely not something wrong with your gas gauge, it's just how they work. At least both of the BMWs that experienced this same behavior had the excuse of mechanical gas gauges. I don't know what the excuse is with the MINI. Just fill up when you're down to three or for candy corns and you'll be fine. The manual even says that you shouldn't be trusting the 'Range' data on the OBC once it gets down below a certain mileage. Plus if you let it run dry you risk the chance of burning out your fuel pump (which I've read somewhere on here).