My ford cars which show miles to empty normally got to red light at about 50 miles from empty. Other cars ive owned in the past used to go a lot further on red and one would turn to red just before it ran out.
Its best not to let a fuel tank get that low anyway so best just to try and keep it topped up.
Be careful. If you let the petrol get as low as that, there is the risk of the fuel pump sucking up small bits of debris from the bottom of the petrol tank, and that could block the fuel system.
I don't usually let it get to the light coming on after what happened when I ran out of petrol once but the garage near work is soooo expensive I'd rather wait til I'm nearer home. As that's only about 15 miles I'm sure I'll be alright.
Nowt wrong with putting a fiver petrol in ya car! whats to be embarrassed about!
for all the garage knows You could be going on a long journey and just filling up your tank that has already got quite a lot of fuel in to start with! I often put a fiver in as i don't like to go on the red.
To run that low on fuel picks up sht from the tank & I believe can do damage to the Cat. Converter. also, if you are stupid enough to run that low when on a Motorway you want your @rse kicking! to run out whilst you may be in the outside lane could cause a pile up.