i don't know if anyone has really done a real study on
how long gas will last sealed and stored..military maybe??
but---my snowblower started up a few days ago with gas that
was left in it from last winter--same with the lawnmower--fired
up with gas left in it over the winter when i got it out in the
spring..i have cans of Coleman fuel--which if not "gas" is close
to it---and its years old--open and closed..it it burns just fine..