tractor racers Ab Jenkins and Barney Oldfield, publicity men for Firestone tires and Allis Chalmers

It was in 1932 that Harvey Firestone, owner of Firestone Tire, had three Allis-Chalmers tractors built, not for their pulling power, but for speed. They were the first tractors to be fitted with rubber tires.

Firestone hired celebrity race drivers, including Jenkins and Barney Oldfield, one of the most famous of the early auto racers, to engage in tractor races at county fairs and agricultural events.

Famed race car drivers like Frank Brisko, Barney Oldfield, and Ab Jenkins performed in front of an estimated 1 million people during 1933 alone.
http://www.agriculture.com/machinery/tractors/antique-tractor/allischalmers-u_201-ar15591

http://www.allischalmers.com/forum/forum_posts.asp?TID=18003&title=barney-oldfield-and-the-allis-chalmers-999
http://blog.hemmings.com/index.php/2009/09/15/land-speed-tractors-oldfield-v-jenkins/comment-page-1/#comment-9772041

There were promotional field demos, pairing a Model U on steel against one on rubber. And to literally drive the point home a fleet of U’s equipped with a high-speed fourth gear raced at tracks across the country.

One of the tractors was on loan to the Ardell Brown Classic Car Center in Salt Lake City in 2004.

Firestone believed the high-speed tractors would be a way he could show farmers that his rubber tires were a technical marvel, not a gimmick.

The agriculture market was skeptical of the new rubber tires. Tractors, at the time, ran on metal rims.

Firestone hired celebrity race drivers, including Jenkins and Barney Oldfield, one of the most famous of the early auto racers, to engage in tractor races at county fairs and agricultural events.

Jenkins eventually took one of the tractors to Bonneville Salt Flats to set a land-speed record. In 1935, he drove the tractor at 68 miles per hour through a one-mile course. He later was given a belt bucket inscribed, "The World's Fastest Farmer."

Eldon Kearl, who facilitated the loan of the tractor, said his research shows the tractor was purchased by a farmer, who found that it had no power but could go fast. It was later purchased by an Ohio man, Randall Sheffied, who planned to use the tractor to plow fields. He, too, found the tractor had no pulling power but went much faster than he wanted. Research told him the tractor was not meant to plow fields but to race.

http://www.deseretnews.com/article/595096478/This-tractor-was-built-for-speed.html?pg=all
http://antiquetractorsforum.com/showthread.php/84-Allis-Chalmers-first-in-rubber-and-racing

War, a New Era, and Depression, 1914-1940 By Paul W. Glad