Later this year, two-time Formula 1 world champion Fernando Alonso will be making his return to the Indianapolis 500 in hopes of finally achieving the coveted Triple Crown composed of a win at Monaco Grand Prix, 24 Hours of Le Mans and the Indianapolis 500. So far Alonso, has complete two of the requirements with only Indy 500 lacking.

For this year's race, the Spandiard has chosen a new number to race with – #66. As to why the number 66, it has a special meaning McLaren as this is the number which they took their first Indy victory with Mark Donohue in 1972.

In all five Indy 500 appearances, Donohue used the #66, together with Roger Penske, and all of his starts with a McLaren chassis. While having raced in Indy since 1969, he was only able to clinch victory in 1972 after leading the final 13 laps of the race with his M16B challengers and even setting a new average speed record in the process. Since then, that race has marked the only win for #66 thus far.

Will Fernando Alonoso

For this year, Alonso's McLaren entry for the Indy 500 will be powered by Chevrolet's twin-turbo V6 as opposed to 2017's Honda-sourced powerplant which expired in the race with 21 laps to go. Chevrolet is also the defending winner of the race, having powered Will Power's racer to victory last year.

Throughout his long Formula 1 career, Alonso has always used the #14 for his cars. In 2017, the McLaren-Honda challenger ran with #29. With a new engine, and a new number, will Alonso be finally able to complete his long awaited Triple Crown.

The 103rd running of the Indianapolis 500 will be held on May 26th, 2019.