Where are they getting fuel? Its several years in to the apocalypse, fuel stations wouldn't pump. Most cars these days are hard if not impossible to siphon and they aren't driving corollas and civics.
It's actually less than two years or so at this point.
Plenty of usable (even if not optimal fuel at this point). Pull fuel lines, puncture tanks, field pumps attached to hoses lowered into gas station pumps etc....