In 1952, the No. 28 Cummins Diesel Special cemented a special legacy at the Indianapolis 500 and also, in many ways, helped reshape the future of the trucking industry. That year, this unique diesel-powered race car captured the pole position - the only diesel-powered racing machine ever to do so - with a one-lap time of 139.104 mph and four-lap time of 138.010 mph. It also helped Cummins validate the use of turbocharging and fuel injection within its diesel engine design. (All photos by Sean Kilcarr/Fleet Owner)