Last weekend, I was driving a car back to Los Angeles. I filled up in Victorville and topped up again near the LAX rental car return. On both occasions, a man approached me asking/begging to put gasoline in his car. They used phrases like "I'm not asking for money, just for gas" and "you can put it in yourself". I did not trust it and refused, as I believe it was a scam.
According to scambusters.org, sobstory panhandlers are a common scam, but in the scambusters example they ask for money, not gas, and scambusters even suggests that offering to buy the gas is a safe response. However, in my case they did not ask for money — just for gas. From scambusters:
Standing around while your gas tank refills makes you a sitting target for panhandlers who hang around the pumps and service areas with a sob story for anyone who will listen.
(...)
Action: It can be tough to say “no” but that’s usually the best response. If you really feel you must help, offer to buy the gas or the food rather than handing over cash.
When someone asks me to buy gas for them, is this a scam? How does it work? It's never happened to me before, but in Southern California it happened two times in a row.