Is it just me or is the coupe petrol light just like most women?

Think they want something they don't particularly need!?

It comes on, stays on for a short while, goes off, back on,off, on, off, on... Etc etc.

Then maybe a day or so later il pop some petrol in, possibly preventing a epileptic fit and of course running out of fuel

From my experience - If you are down to your last 1/4 and put your foot down the light will come on. Drive lightly and it'll go off with around the same capacity of fuel....
I think it must be sensitive to pressure from the engine under load when you still have enough gas for a good few miles.

My marea is exactly the same. But I suppose it will be being the same tank and sender as a coupe.
Shows a quarter then when accelerating the light comes on and it says it's empty.

All fiats I have had are the same! I think the senders are virtually instant, so they react to cornering and acceleration. I had a Saab 9-3 which had a much slower sender, meaning the reading was always the average of the last 5 minutes or so, making the gauge much more steady.
When the red light came on, it actually meant you were low on fuel. The red light comes on in the Coupe and it only needs 50 litres to fill it! Could have done another 80 or so miles.

The fuel sloshes around; the light is set by a circuit in the fuel gauge (not a separate switch). What would you expect?

It's a coupe. Fill it up at 360 mile whether it needs it or not!

I ignored your advice before Neil, I tried taking it past 456 miles, on the way to MITCAR, with a car full of people.

I didn't make it on time...

You should try a car from the 70's..the fuel gauge is mainly an approximation of how mich juice you have left.

The Coupe gauge is very good in comparison.

I reckon on 30 miles once the the light comes on to avoid running out.

The light is approx 1 - 2 gallons of petrol left in the tank, but it's up to you how much petrol roulette you want to play. In winter, my fuel gauge stops working, so it always says it's empty, so that's fun trying to work out if I need petrol or not. The general give away if I do, is the noisy fuel pump (have a separate one in the boot) gets err... noisier!

Mrs Nello was not too impressed back in the day with my old Beta HPE when I assured her I had loads of petrol for the day out and we broke down on the Coventry Ring Road.... The light would come on in that with half a tank and a tight bend!