How long does it take for a snickers bar in a gas tank to make the car stop running?

A snickers bar in a gas tank may never make the car stop running. This is because there is a filter between the fuel tank and the vehicle’s carburetor or fuel injector(s). This filter could be anywhere between the tank and engine depending on the make & model of vehicle. The intake hose that the fuel enters to leave the tank also may have a filter. Foreign matter may clog these filters, which are replaceable, but will rarely find its way to the engine.