How accurate is the fuel left display on your BMW

drugekull

New member
Hi Guys

This might seam like a stupid question but I was wondering the other day how accurate that KM's left before fillup display is.

I have a e90 the other night I parked my car in the garage and it had about 70km left before i had to fill up. The next morning I stated it up drive for a bout 10km's then it it said you have 9km left.

I took a 323i for a test drive bfroe I bought mine and the KM's left display said 0 but I still drive it to the petrol station which was abotu 4 of 5 km's awayt to fill it up

One of the sales guys recently let me drive his 135i Coupe when we left the dealership it was at 10km left I asked him if he needed to put petrol he said na its plenty left. I drove the crap out of this car on the high way and in the town streets flat footed all the time it started saying 0 left when i got on the hgihway and I still drive it anouter about 10km with no indication of it running out of juice

Do they build in some sort of safty margine if so does anyone know what it is
 

Hellas

///Member
The km left is a calculation between the readings that the computer get from the two tank sensors and the immediate way you drive (eg connected to the l/100km gauge)

It takes some time for the values to adjust. Example: I drive a diesel, so the changes are very erratic. I drive like a granny after filling up, and my km left goes up to 1200km left. Then I plant it for 20km and the km left falls to 750km left. Once I start driving normal again, the km left will go up again and so forth.

Hope this clears things a bit. Between the time/way you parked off last night and started up this morning, the PC has taken all factors into account to calc a value.

So to answer you question: No, the km left gauge is NOT pin point accurate and you should really not try and test it below 100km left :)

To add, I have heard of people going up to 80km after the gauge went to zero, so I would say you have about 5-10liters left after zero.
 

tyu333

Member
I once got stuck on my way to fill up and it said I have 36km left. So now when the orange light comes I fill up.
 

Chucky

Active member
my Car Does not have OBC so when the dail is in the orange or on the empty line that means its time for me to put in some petrol LOL :thumbs:
 

Dmonic1

Active member
Dont dont EML light come on and the car goes into limp mode when fuel is too low? it does on my 335i
 

drugekull

New member
Chucky said:
drugekull said:
Thats so low tech Chucky :)

low tech never left me strandedor stuck on the side of the road :drama:

You Know I actually agree with you

I learnt that lesson when I got stuck at the side of the road 3 times with my Alfa 156 Selespeed interesting Idea for a gearbox but had one huge defect it was made by Alfa
 

zaleonardz

Well-known member
According to my wife, its super fscking accurate, she will always drive it until there is like 10km left before its out...

:cry::argh::argh:
 

Chucky

Active member
I had a silver 147 sele, what a beautiful piece of junk :yuck: IMO

oh that had OBC i still didnt trust it for two reasons regarding fuel,
1.It was an Alfa
2.It was an Alfa



 

drugekull

New member
I think it also depends on what BMW you have the ones that are lighter on fuel will be more accurate that someone that has a M3 or M5 or even a 335i

just for the reason that they can really turn on the taps on those cars
 

AshG108

///Member
And whats worse with getting stuck for petrol and you driving a sleek as hell BMW, rather jsut fill it up when it says 20km on the clock, mine went down to 10km, then i fill. when i test drove it, it said 2km left but i dont worry, i dont like running on reserve anyway
 

Fordkoppie

///Member
I have run out on my way to fill the car up at 12km left according to the obc. Yea right!
The reason for the 335 going into limp mode is because it is very dangerous for the engine to run lean (the moment it starts running out) if it should be boosting under that circumstance.
 

Prev

Administrator
Staff member
I got stuck with it showing 42km to go :argh: very embarassing but luckily 1 of my buds were close by and came to the rescue :thumbs:
 
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