Ray Harroun, in charge of the United States Motor Company team, develops a fuel-sipping carburetor that runs on kerosene. Driver Willie Carlson's Maxwell chassis proceeds to run the race to an eventual ninth-place finish on a mere 30 gallons; with the price at $0.06 a gallon, Carlson's total $1.80 fuel bill stands as the most economical performance in motor racing history. 1915: Ralph DePalma's Mercedes again begins to slow with connecting rod problems late in the race. This time though he makes it to the finish to win. 1916: Dario Resta wins the race, which was shortened to 300 miles (500 km) due to the ongoing war in Europe. The field of 21 cars is the smallest ever. Later in the year, the Harvest Auto Racing Classic is also held. 1917–1918: Race is not held on account of World War I. Other tracks continue to host smaller events, but Indianapolis voluntarily suspends the race. Though closed to racing, the Speedway is used as an airstrip, serving as a fuel stop between Air Force bases in Dayton, Ohio and Rantoul, Illinois. 1919: With the track reopened after the war, local Indiana-born driver Howdy Wilcox breaks a four-race winning streak by Europeans. There are 19 rookies who start this year's race, the most newcomers in one Indy 500 field (if one discounts the "all-rookie" field of 1911). 1920–1929 1920: Ralph DePalma suffers another heartbreaking mishap when his magneto fails with 14 laps to go while leading. Gaston Chevrolet takes over the lead and goes on to win. Six months later, Chevrolet is fatally injured in a race at Beverly Hills. He becomes the first '500' winner to die. 1921: Tommy Milton, Gaston Chevrolet's replacement on the Frontenac team, drives through the field from 20th starting position to win his first '500'. Ralph DePalma again dominates the first half of the race, only to suffer mechanical failure. DePalma's career record total of 612 laps led will stand for the next 66 years. 1922: Jimmy Murphy is the first driver to win the race from the pole position. 1923: Despite suffering loss of circulation and blistering in his hands due to shrinkage of his tight-fitting, 'White Kid' gloves, Tommy Milton becomes the first driver to win the race twice (Milton was relieved by Howdy Wilcox for laps 103–151). 1924: Lora L. Corum's car is taken over by Joe Boyer, who goes on to win.