What invention in the 1910s increased the popularity of gasoline cars?

In 1912, Charles Kettering’s electric starter, introduced in gasoline-powered Cadillacs, increased the popularity of gasoline cars. Prior to this development, gasoline engines typically needed to be started by turning a hand crank, an inconvenient and even potentially dangerous task. Kettering’s starter was subsequently adopted by other car companies and used widely in gasoline-engine cars.