Fernando Alonso will run with No. 66 on his car when he makes his return to the Indianapolis 500 with McLaren Racing in May.
Fernando will be making his second appearance with McLaren at the 103rd running of the 500, having starred on his debut in the race in 2017, when he was entered as #29.
The choice of #66 is to honor McLaren’s first victory at the Brickyard, achieved with Mark Donohue’s Penske-run M16 in 1972.
Donohue used #66 on all five of his Indy 500 appearances with Roger Penske, including his debut 50 years ago, and both of his starts with McLaren chassis.
Donohue and Penske were usually closely associated with #6, which they used in various forms of racing, prior to making their first Indy 500 entry together in 1969. That year AJ Foyt was running as #6, so Penske opted to run #66 on his Lola.
Prior to then cars carrying #66 had started the Indy 500 just six times, in 1935, 1947, 1959, 1964, 1965 and 1966. The entrant on the second of those occasions was famed car maker Preston Tucker (played by Jeff Bridges in the 1988 Francis Ford Coppola movie, Tucker: The Man and His Dream), while NASCAR legend Cale Yarborough was at the wheel of #66 in 1966.
Donohue made an impressive 500 debut in 1969, qualifying fourth, finishing seventh, and winning the Rookie of the Year Award. On his second outing in 1970, also with a Lola, he started fifth and finished runner-up.
For 1971 the Penske team switched to the new wedge-shaped McLaren M16, running Donohue’s dark blue car alongside the two papaya works entries of Peter Revson and Denny Hulme. Revson took pole and eventually finished runner-up, while Donohue started second only to retire with a transmission problem – by unfortunate co-incidence after completing 66 laps. Later in the race his parked machine was badly damaged when hit by a spinning car. That year Donohue would go on to win at Pocono and Michigan with the #66 McLaren.
In 1972 Revson and Donohue qualified their new M16Bs second and third at Indy. After the works car retired early the Penske entry went on to score a comfortable victory in a race of a high attrition, leading the final 13 laps and setting a new average speed record. It was the only win logged at Indy thus far for #66.
In 1973 Donohue made his final 500 start running with #66 for Penske, qualifying his Eagle third and retiring with an engine failure.
The following year the Penske F1 team used #66 for Donohue’s first outings in Canada and the USA with the new PC1 chassis – the traditional #6 was not available because it was used that season by McLaren for Denny Hulme.
The #66 was raced six times at Indy in the eighties and nineties by various drivers and teams, including the 1986 Mike Curb entry for Ed Pimm – whose crew chief was Robert Fernley, now the President of McLaren IndyCar.
However, after Donohue’s 1973 Indy outing Penske revived #66 for the 500 on just one occasion, when in 2001 the team returned to the race after being absent for five years during the split between the IRL and CART. Current McLaren sporting director Gil de Ferran qualified his #66 car in the middle of the second row and finished runner-up to team mate Helio Castroneves. Since then a #66 car has only been raced once in the 500, in 2018.