how much left ?

[Jocko]

I had to replace the fuel tank in a 12 year old Cavalier with 153,000 miles on the clock. We removed the metal tank, and drained every drop of fluid out of it. There was not a drop of water in it.
Water in petrol is something I never give a thought to.

[sparky Paul]

I had to replace the fuel tank in a 12 year old Cavalier with 153,000 miles on the clock. We removed the metal tank, and drained every drop of fluid out of it. There was not a drop of water in it.
Water in petrol is something I never give a thought to.

You don't need to, because you rarely get condensation in car petrol tanks. Petrol turns to vapour so readily, it fills the space left behind as fuel is used. Modern plastic tanks are even less likely to make condensation.

Diesel is a different matter. Because diesel does not readily turn to vapour, air is drawn in, and condensation can certainly be a problem.

That said, you still need a fast drop in temperature outside the tank to cause condensation, which isn't normally a problem. Condensation is a major problem in aircraft, where they experience fast temperature and pressure drops, both of which will provoke condensation.

[John A]

That said, you still need a fast drop in temperature outside the tank to cause condensation, which isn't normally a problem. Condensation is a major problem in aircraft, where they experience fast temperature and pressure drops, both of which will provoke condensation.

There's drains on aircraft fuel tanks and still there can be a problem with Cladosporium resinae where there's a join between the fuel and the jet fuel https://en.wikipedia.org/wiki/Microbial_corrosion

But, given the state of our roads, the water if any, plus fuel gets agitated so much that I'd be surprised to see water in a diesel cars tank that is driven regularly / gets fuel from a garage. By contrast the amount of prolonged shaking an aircraft encounters is very much less, hence the problem even though there is stringent care taken with the jet aircraft's fuel.

[JohnAlways]

Back in the days I just to repair trucks there were little glass water traps in the fuel lines that you could drain until the diesel ran out when you peonptly (or not) closed the drain valve. They were glass so you could see the water with the fuel floating on top. Those were the days we had to light a fire under the fuel tanks because they had waxed up

[desthemoaner]

I discovered soon after picking my Jazz up from the dealer that the fuel empty light gives oodles of warning before the car actually runs dry.

When we test drove the car, the fuel light was on. After we bought it, the dealer put a fiver in the tank before we drove away and I put another 8 quids worth in on the way home. Despite all this the fuel light stayed on till I put a further tenner in next day.

Not sure whether this early fuel warning is good or bad, because it could go either way. If the "0 miles to go" message doesn't scare you, then you could end up adopting a mindset that there's bound to be plenty of fuel left when the light comes on, and that could lead you down the road of complacency.

[Jocko]

When we test drove the car, the fuel light was on. After we bought it, the dealer put a fiver in the tank before we drove away and I put another 8 quids worth in on the way home. Despite all this the fuel light stayed on till I put a further tenner in next day.

I think the hysteresis is quite high on the light circuit. Other cars I have owned, the light flashes as you go over bumps and round corners, until eventually it stays on. The Jazz light comes on then locks on. It is as if it comes on when you have a gallon left then doesn't go out until you put five gallons in!

[stesjazz]

I got 50 miles of town driving,with the light on until it ran out of petrol, half a mile from home with my parents in!!!  lol but i just wanted to see just how far i could go......but i always put some in now, when the light comes on.