Not that it's going any further but...

Bearing in mind that the end of the fuel suck pipe is pretty low in the tank, why should it pick up more crud when the tank is nearly empty than at any other time?

Rob Graham

The message from Warwick contains these words:

I suspect it's fairly hit and miss even between identical models. It's fairly hit and miss even on the same car sometimes - fuel gauges are pretty inaccurate.

Mind you - I got to /below/ the red on my Audi last night, which was a bit scary. That must have been 75 miles after the warning light came on.

The message from "Rob graham" contains these words:

I suspect it's partly myth and partly because the very low fuel level sloshes around on the very floor of the tank. Try disturbing the sediment by rocking to and fro in a full bottle and one with only a splash in the bottom.

Handbook for my diesel Citroens usually say between 6 and 8 litres, so I'd expect similar from your Pug. I used to get about 85 miles out of the ZX at normal speeds after the light came out. And yes, I know this cos I ran out a couple of times. Never sucked any crap into the fuel system as far as I'm aware though.

Gauges are inaccurate though. My Punto apparently has 6 litres in it when the light comes on. I got 80 miles out of that yesterday and it's NOT that economical..

Mike

Once my orange light comes on no my celica I have no more than 20 miles at motorway cruise speed before i start to stutter, once the first stutter has happened i have no more than a mile to get fuel. Done it twice now on days when ive forgotten my wallet. But i took my tank off during the winter and checked inside - clean as a whistle, still silvery metalic inside.

The light on my Coupe (Hyundai) is triggered by a thermistor in the tank as opposed to the float-controlled gauge and hence is probably quite accurate (across all models too).

I had assumed, perhaps wrongly, that all (most) cars were of this design?

Mathew

Yes, I suppose so.

Rob

Nearly everything has a plastic tank these days too, so you've got to try pretty hard to get lots of rust and crap in the tank...

By a thermister? How would that work? Until the whole system has been up and running for a while the fuel will be at the same temp as ambient and everything else?

The current through the thermistor causes it to heat up slightly (called 'self-heating') - whilst immersed in the fuel this heat is dissipated and hence the resistance stays high. When exposed to air this is not the case and hence the resistance drops as the temperature increases (at which point the lamp illuminates).

Here's the schematic (not that it's directly relevent to the your query):

That's a useful guide. I'm not willing to run a diesel empty since I don't know how to prime it yet.

I'll go no further than 30 if I run it that low again.

I tend to fill up before the lamp comes on anyway and treat the lamp as 'fill up now'. If I ever find out how to prime it though, I may just fill up and drive as economically as possible to see how far the damn thing will go until it judders to a halt. All the while carrying a gallon in the boot of course.

Regards

Warwick