Mike Conway, Kamui Kobayashi and Jose Maria Lopez opted to make the change because they were dissatisfied with the balance of the pole-winning car in race trim during the final qualifying sessions on Thursday.
"We weren't 100 percent happy with the balance of the car basically," said Conway. "We wanted to tweak it a little bit, but instead took something that we knew was proven.
"It was a known proposition even though the tyres have changed a little bit [since last year]."
Conway explained that the change was "more about having a well-balanced car" than outright pace, and the #7 crew tried the new set-up in the warm-up on the morning of the race.
He added: "It wasn't night and day, but everyone was happy and we said that we'd stick with it."
Podium: #8 Toyota Gazoo Racing Toyota TS050: Sébastien Buemi, Kazuki Nakajima, Fernando Alonso, #7 Toyota Gazoo Racing Toyota TS050: Mike Conway, Kamui Kobayashi, Jose Maria Lopez