PVC I haven't tested it yet, but a quick google search found some positive results, some solvents do make PVC soft, but gasoline does not, check this out:

http://www.spudfiles.com/spudtech_archive/viewtopic.php?t=7896

I'll throw a small chunk in a glass of gas at home tonite & measure it before & after
a few days soaking & do my own tests.
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2002 owner since 1980