The nanny left me alone!

[PropellerHead]

I've been driving BMW's with the high OBC (larger display at speedo is most telling) for 13 years. Every single time I get to the right spot in the remaining fuel, I get the comforting fuel nanny 'gong!' that says, "HEY! 34 (or however many) miles to empty!

So, today, I'm truckin' on down in a trip that runs about 400 miles. Thinking about that thread where folks get 400 miles on a tank and yeah.. the low fuel light is *on*, but the car has been quiet. I'm at 395 miles on this tank and not a whisper! Must not be 34 miles to empty yet, right? I make it to the hotel today and after check-in, the OBC says Aughghghghghg!!!! TWO!!! COUNT 'EM TWO MILES till empty!!! AUGHGHGHGH!!

Ok. In fairness, I might've added a little to what it *actually* said. But it did freak me out. 2 miles? No nanny gong? Hell, if I had chosen the restaurant instead of the hotel, I'd have ended up coasting into the emergency lane with zero gas. I was totally relying on the nanny to keep me safe!

Well, no more! I filled up, washed the bugs off my freshly polished windscreen, and will ne'er again count on the nanny to keep my misbehaving OBC in line. Mark my words.. and from now on.. Mark my mileage.

[TerminatorX5]

in those cases i usually push in the button on left stalk to get to miles info and have in front of me - just in case

[absentmathis]

I decided long ago not to trust my BMWs to tell me when they need gas. Surprising though that it apparently didn't alert you. Maybe you missed it...windows down or stereo noise.

[Ricky Bobby]

Originally Posted by TerminatorX5

in those cases i usually push in the button on left stalk to get to miles info and have in front of me - just in case

x2 I usually keep the range on display all the time, its fairly accurate for the most part and I barely have to run it down to single miles till empty anyway.

[Shled]

You know the gong/nanny/OBC warning guesstimates remaining mileage UNTIL you start using the reserve portion of fuel in the tank right. In my car, that is an additional 2.5 gallons.

[Cole]

I agree with this, BMW always leave a bit in hand and it will never run out on exactly zero miles to go. I have pushed mine to very close to the limit, and then on fill up, it will only take +/- 80 litres. Since it is supposed to have a 90 litre tank (X530D) this implies that I still had 10 litres left!

PropellerHead, I would be interested to know how much you were able to get in your tank if you did a fill up to the brim?

Originally Posted by Shled

You know the gong/nanny/OBC warning guesstimates remaining mileage UNTIL you start using the reserve portion of fuel in the tank right. In my car, that is an additional 2.5 gallons.

[TerminatorX5]

I filled up once 24.058 gallons - that is in one single "swoosh", without topping off the gasoline "gun" until things spill... even though i thought that the tank is 24 gallons, i guess there is always room in the filling tube or something... lol...

[Qsilver7]

Originally Posted by Shled

You know the gong/nanny/OBC warning guesstimates remaining mileage UNTIL you start using the reserve portion of fuel in the tank right. In my car, that is an additional 2.5 gallons.

Just an FYI...not trying to make any waves...we're probably on the same page...using different wording.

The interpretation/understanding I get from the owners manual & BMW's docs is that the "reserve" isn't an "additional" 2(+) gallons (reserve amount is based on which engine you have)...but is the last 2(+) gallons in the tank.

For instance, the OM infers that the reserve is "included" in the total fuel tank amount:




The fuel level sensors sends data to the IKE, which then initiates the low fuel warning...and probably if you have TEST 6 up...the remaining amount of fuel in the tank will probably be equivalent to approx 2 gallons (will need to convert the liters displayed) when the low fuel light illuminates.

(screen 1 of TEST 6 will show the reading of the left & right fuel level senders...plus an approximate amount of fuel remaining in the tank)



(Screen 2 from TEST 6 will give an approximation of total amount of fuel left in tank)

[Ricky Bobby]

Wow I like Test 6! Nice!

And T, looks like you filled up enough to only have about a half gallon left of fuel once! (since it looks like the 24.6 gallons included 2.1 gallon reserve)

Way to suck those fumes down the engine hahaha!

[Qsilver7]

Originally Posted by Ricky Bobby

Way to suck those fumes down the engine hahaha!

Definitely had the X5 guardian angels by his side...64 oz of fuel in a 24.6 gallon tank...could have stalled the engine if on an incline or hill...that's a lot area for 64 oz of fuel to cover...and not reach the fuel siphon pick-up thingy.