1915 Grand Prix season

Sources:[1][2][3][4] This year the Grand Prize and Vanderbilt Cup’s engine limits were both matched to those of the Indianapolis regulations - down to 450 cu in.

Then Indianapolis lowered their engine limit down to 300 cu in (4.92 litres) along with the additional restriction that only three cars from each manufacturer could be entered.

It ran for virtually the whole length of the year, from January to November held at seventeen separate venues with a total of 27 races.

[7] Naturally the biggest fields were at the three blue riband events, the American Grand Prize, the Vanderbilt Cup and the Indianapolis 500.

Ralph DePalma had upgraded his older Mercedes with the 18/100 car that Louis Wagner[11] (or Lautenschlager[6]) had raced at the French Grand Prix.

[12] Claude Newhouse was running a Delage Type Y. Barney Oldfield was fastest in qualifying, but it was British driver Dario Resta in his Peugeot that dominated the race.

Resta carried on to win by 6 minutes from Howdy Wilcox, with Hughie Hughes third in his FIAT Special (fitted with a Pope-Hartford engine[13]).

Alley went wide and ripped up 50 metres of fencing along the roadside, then his teammate O’Donnell hit a hay-bale and rolled but was uninjured.

But with only five laps to go, Ruckstall’s car broke its axle and then Pullen had to pit to tie down his fuel-tank that had been shaken loose.

The pressure off, Resta cruised to a consecutive victory seven minutes ahead of Howdy Wilcox who inherited a lucky second place.

Ralph DePalma was racing his Mercedes GP which set up an intriguing rematch from the epic contest from the previous year.

The front row also included DePalma (Mercedes) in second, Resta (Peugeot) third and Cooper (Stutz) on the outside and the cars were numbered according to their grid position.

Van Raalte (travelling under his wife’s surname, “Graham”, to race during wartime) had used Barney Oldfield to qualify his Sunbeam further up the grid.

For those spectators who did turn up on the Saturday, Ralph DePalma put on a display of his team’s quick tyre-changing pit-stops – changing a front tyre in only 19 seconds.

However, when a retro-active points system was calculated in 1927 it was Earl Cooper who was unofficially awarded the championship after winning five races and getting four seconds.