The rule of thumb is that properly stored gasoline has a shelf life of approximately 90 days before serious degradation sets in, but as always, there’s a catch or two. First, you never know old the gas you just purchased is. It may have left the refinery yesterday, or it could have been in storage for a month before you pumped it into your tank. Second, what constitutes “proper storage?” While there are several good answers, a half full motorcycle tank, parked in a non-temperature-controlled environment like your typical garage, isn’t one of them. The bottom line here is that, if you use your motorcycle on an infrequent basis, or leave it parked over the cold dark winter, a can of stabilizer is cheap insurance.