When should the fuel light come on? How many miles left?

[M3KUK]

As above, I was going to post that my fuel light wasn't working, but It just came on with 18 miles left on OBC?
My E36 and E46's lights come on with 60 miles left?

[Brianmoooore]

Should be with around 5 litres left, so around 30 miles if you drive with a light right foot, 20 if you don't.

[Cloggy Saint]

I've never seen my fuel light come on in 16 years of ownership and I've run it pretty low on occasions. I replaced the bulb a few years back assuming it was dead and still it's never come on. I want to see it!

[Brianmoooore]

Either convert your car to LPG/duel fuel, and run the petrol tank dry, or stick a 5 litre can of petrol in the boot and do the same.
Most people assume that when the gauge needle reaches the red it should come on. This is incorrect - it should come on when the needle reaches the lower end of the red section, and enters the section that actually lights up.

[M3KUK]

Yes Brian that's sounds right, the later 3 series light comes on when you enter the red.
I filled a can and was going to see how low it went. It came on at 18 miles flickered a
bit then stayed on. The OBC miles left then started going up! God I love these cars!
Never a dull moment!

[Sanchez]

I never want to see it, means she's thirsty and need s£50.

Plus running low sucks any crap that maybe I the bottom of the tank to go into the filter.

[M3KUK]

Yes just wanted to see if the light worked!

[Brianmoooore]

Plus running low sucks any crap that maybe I the bottom of the tank to go into the filter.

Not really true. The pump draws from a cup welded to the bottom of the tank, which is constantly flushed by returning fuel from the engine.
If there's enough rubbish in the tank to cause problems, it time it was cleaned out.

[M3KUK]

My E46 M3 tells on you, if you low fuel it, take it below zero miles left, it logs it.
My Mechanic is always bollocking me for doing it!

[Mr-Lachs]

My E46 M3 tells on you, if you low fuel it, take it below zero miles left, it logs it.
My Mechanic is always bollocking me for doing it!

Haha brilliant!!

[reggid]

mine comes on with about 8 litres left

[jmc330i]

I tend to fill up when the light comes on when I'm just pottering around locally. Usually get 55 to 56 litres in a 63l tank, so around 7 or 8 litres left.

[HairyScreech]

If I am not doing any distance and only running around locally I never bother putting fuel in mine until it comes on.
How have you managed to last so long without seeing it come on?

[kieran325]

I'm another who hasn't seen the light on the 325 and I've had it 22 years!

[e30topless]

I'm another who hasn't seen the light on the 325 and I've had it 22 years!

Fuel these days isn't as good as it used to be, I heard/read things like it varnishing and losing Octane in as little as a few weeks, some guys notice the difference in between Mapping !


It may be a good idea with how little miles you do in your rust bucket to run it right down, and take a look at the light and fill up with fresh juice !

[kieran325]

I don't think I've tanked the 325 since June last year when it went for the MOT

I like to fill it up when it touches a quarter and crack on. The M5 on the other hand lets you know when it's on its reserve when it touches the quarter!

[HairyScreech]

I think the later cars actually put the light on when the OBC thinks the car has 40 miles left in the tank.

I know the Z3 does as it can be highly unpredictable when it will come on if you go by the gauge but always lights at 40 miles on the OBC.

[Jona1971]

My light came (first time ever) with the needle just below the red. Apparently, there's a gallon left at that point, but my bottle went and I filled up then.

[Cypriotgeeza]

In my M30..normally when there's about 5miles left

(I joke I've never seen mine on either..wondering if it actually works )