The thin steel float used in my car (which was built in the UK in the early 60s, which I'm assuming is why it's not originally plastic) has rusted to a point where it's leaking in fuel and therefore failing to operate as desired.
I'm planning to replace it with a plastic float, but obviously want to make sure I'm not using something that could dissolve in the petroleum. I notice that 5 litre plastic canisters are HDPE so I intend to use that, but I'm intrigued as to just how much it matters. Plenty of discussion around the net suggests that most plastic bottles are likely to dissolve, most of which in my experience are PET. But this chart suggests PET is as good as HDPE:
That chart doesn't have data on PP or PE interestingly (though I assume HDPE has the same properties as PE).
So my question, respecting that storing petroleum in plastic containers not explicitly rated for the task is a bad idea, which plastics will actually dissolve? If it's a grey area is there a minimum thickness?