Franklin cars were technological leaders, first with six cylinders (by 1905) and automatic spark advance, in 1907. Demonstrating reliability, L.L. Whitman drove a Franklin from New York City to San Francisco in 1906 in 15 days 2 hours 15 minutes, a new record. Franklin were undisputed leaders in air-cooled cars at a time when virtually every other manufacturer had adopted water cooling as cheaper and easier to manufacture. Before the invention of antifreeze, the air-cooled car had a huge advantage in cold weather, and Franklins were popular among people such as doctors, who needed an all-weather machine. The limitation of air-cooling was the size of the cylinder bore and the available area for the valves, which limited the power output of the earlier Franklins. By 1921, a change in cooling—moving the fan from sucking hot air to blowing cool air—led the way to the gradual increase in power.