Hi all. I let the car run low on fuel on purpose just to see when the light came on as I knew it worked as the light is there on start-up. It eventually came on when the needle was actually on the empty line. Is this normal with this car? And if so, how much fuel is actually left in the tank at that point?

Thanks as always.

Mine comes on when there is 50 miles of range left according to the trip computer, so about a gallon - and yes, the fuel gauge is in the red zone showing empty.  I have very occasionally allowed the range to drop to less than 20 miles left before refilling, although I think there is still some safety margin there and you can go to zero and still have some reserve (but I have never tested this).  I seem to remember Top Gear did this to see if they could cross Europe on a single tank full, and go to wherever they were going with it showing zero miles left.

On most Mk3's there are 8 litres (approx 100 miles) left in the tank when the light comes on despite the fuel computer saying there is far less. Easy to tell as you can get 45 litres in when you fill up and it's a 53 litre tank

The OPs car is a Mk1 Focus, so Mk2/3 stuff isn't really relevant.

My gauge spends a good 50+ miles looking empty, the light comes on at 50 miles, then beeps at 25 miles, and flashes below (I think) 10 miles...and even then I can't get any more than 49 litres in (53 litre tank).  However, I did the same with the Mk6 Fiesta and found the opposite...  I managed to get more litres in than the official tank capacity...and still had 25 miles on the range!   You're usually left with about a gallon (4.5 litres) left when the red light comes on, so that'll obviously go quite quickly in a petrol compared to a diesel.

I also try not to push it too far, in case I corner to hard or climb a steep hill and the remaining diesel flows away from the pick up.   

 

15 minutes ago, TomsFocus said:

The OPs car is a Mk1 Focus, so Mk2/3 stuff isn't really relevant.

My gauge spends a good 50+ miles looking empty, the light comes on at 50 miles, then beeps at 25 miles, and flashes below (I think) 10 miles...and even then I can't get any more than 49 litres in (53 litre tank).  However, I did the same with the Mk6 Fiesta and found the opposite...  I managed to get more litres in than the official tank capacity...and still had 25 miles on the range!   You're usually left with about a gallon (4.5 litres) left when the red light comes on, so that'll obviously go quite quickly in a petrol compared to a diesel.

I also try not to push it too far, in case I corner to hard or climb a steep hill and the remaining diesel flows away from the pick up.   

 

You shouldn't have to worry about fuel flowing away, cars generally have a small reserve, like a swirl pot which gets re-filled when you're back on a straight/flat.

The biggest issues with it getting too low, is pulling any crud from the bottom of the tank.

2 minutes ago, alexp999 said:

You don't have to worry about fuel flowing away, they have a small reserve, like a swirl pot which gets re-filled when you're back on a straight/flat.

The biggest issues with it getting too low, is pulling any crud from the bottom of the tank.

The pot isn't all that big though, on a long sweeping bend or a long steep hill...I'm not sure how long it would last!  Used to have issues quite often on the Peugeots with low fuel and long right hand bends, the fuel would run away from the lift pump and let the fuel pressure drop so much it would cut out - no power steering half way round a corner isn't fun lol.  The other issue with being a DV6 and no lift pump...if it does cut out from lack of fuel, it may not start again without a hand primer.  

The crud on the bottom of the tank isn't really relevant now, it's from back when tanks were made of metal and would rust, there's not usually anything to note in a plastic tank, even after 10 years/150k miles.  Unless people use poorly filtered veg oil that is...  Bought this non-runner a while back...that's actually lumps of chip-shop batter in there!  

Thanks for the replies guys. There is no red section on my gauge, just the lines for empty, quarter and so on. When I switch the car off the needle goes quite a way below the empty line, although I'm not taking this as being fuel.

A word of warning people...I'm a traffic cop and patrol the motorways of West Yorkshire, many of which have recently been "upgraded" to Smart motorways (ie no hard shoulder) and we frequently encounter motorists who have played "fuel tank warning light roulette" and have lost, resulting in them coming to an abrupt halt in a live lane.

The worst case was a young girl in a VW Beetle who spluttered to an abrupt halt in lane 3 of 4 and about 90 seconds later got smashed by another vehicle doing around 70mph whilst she was in the process of getting out of her car. Luckily she survived, but had some nasty injuries as a result.

I could go on but I hope you get the gist....DON'T RISK IT...WHEN THE FUEL LIGHT COMES ON, IT'S TIME TO FILL UP !!!!!! 

I had a MK1 Focus and remember very well that the needle goes a long way below the empty line before you actually run out petrol. I have done around 40-50 miles when the warning light has come on (with no distance to 0 display), albeit quite gingerly. 

As Phil has said above, I would never drive on a motorway if I thought I was going to conk out... Its a stupid idea.

Luckily for me I 'tested' my old Focus' fuel capacity on small city roads near to my house where I could kerb the car if it ran out. Therefore, I knew approximately how far it could go before actually being hitting zero. To this day have never run out of petrol 

I am due to sell it soon and will try and get a picture with it running on fumes to show you how far below the red zone my gauge goes.

1 hour ago, Phil 3747 said:

A word of warning people...I'm a traffic cop and patrol the motorways of West Yorkshire, many of which have recently been "upgraded" to Smart motorways (ie no hard shoulder) and we frequently encounter motorists who have played "fuel tank warning light roulette" and have lost, resulting in them coming to an abrupt halt in a live lane.

The worst case was a young girl in a VW Beetle who spluttered to an abrupt halt in lane 3 of 4 and about 90 seconds later got smashed by another vehicle doing around 70mph whilst she was in the process of getting out of her car. Luckily she survived, but had some nasty injuries as a result.

I could go on but I hope you get the gist....DON'T RISK IT...WHEN THE FUEL LIGHT COMES ON, IT'S TIME TO FILL UP !!!!!! 

I 100% agree, although most cars have a significant "reserve" some people really don't have any sense and will continue to drive on a motorway even when the fuel light has been on for well over an hour.  In my book there is a name for people like that (but the forum censor won't let me use it!) 

years ago my brother leant his vauxhall cavalier to a friend. the friend ran it out of petrol and said it was not his fault as the petrol warning light never came on. well, it did not have a warning light as not many cars did in those days. But it did have a good working petrol gauge. what an idiot.

But it was worse then that. the car needed coolant topping up now and then. My brother kept some water in the boot in a  red plastic petrol can. so when the friend ran out of petrol he found this can in the boot and put the water in the fuel tank and tried starting it, so the car then had water in the tank/pipes/carb. 

So two stupid people - the friend who was too stupid to take notice of the fuel gauge and my brother for lending his car to someone when there was a petrol can in the boot containing water (actually I would have sniffed it first and not assumed it was petrol).

But the real message is, no one should rely on a warning light, look at the gauge and top up the fuel well before it is at the bottom.  you won't save money by refusing to add fuel until the last possible moment

Just now, isetta said:

So two stupid people - the friend who was too stupid to take notice of the fuel gauge and my brother for lending his car to someone when there was a petrol can in the boot containing water (actually I would have sniffed it first and not assumed it was petrol).

When I moved out, I left two fuel cans in the garage.  One was red with petrol in it.  The other was silver with diesel in it.  Guess which was used in the petrol mower shortly afterwards...  

 

I think knowing your car is important, I will push the fuel gauge a bit on mine, but I always fill to the brim and reset the trip meter so know roughly how many miles I should get, and check the range reading as well.  I also work out roughly how many miles I'll do when nearing the end of the tank, so fill up at around the 25 mile marker on the range after a bit of town, or earlier if I have a motorway trip coming up.  

This is about getting to know ones car as Tom has said, and I would never dream of going near a motorway with very little fuel, that's just idiotic.

Thanks again everyone for the replies.