Mexican rookie Pato O'Ward and front-row starter Scott Dixon drove the fastest laps in Friday's final Indianapolis 500 practice while pole-sitter Marco Andretti was troubleshooting ahead of Sunday's race.
A trouble-free final two-hour session at the 2.5-mile (4km) Indianapolis Motor Speedway oval saw most teams test their cars in race conditions after last weekend's time trials.
O'Ward, starting on the outside of row five in the 33-car field, set the practice pace at 225.355 mph in his Chevrolet-powered Arrow-McLaren.
"It has just been really important to try and get the best car under us for race day," O'Ward said.
"Traffic running is going to be key. It's so important to have a car that's able to follow closely and get runs on people."
New Zealand's Dixon, the 2008 Indy 500 winner starting in the middle of row one, was next on 224.646 mph. He won the year's first three IndyCar races and leads the chase for a sixth career season points crown.
"The car felt really good, fast in traffic," Dixon said. "It pulls up wicked fast. Hope that proves true in the race."
American Alexander Rossi, who won the 2016 Indy 500 as a rookie, was third on 224.599 mph, just ahead of Japan's Takuma Sato, the outside front row starter who was fourth on 224.580 mph.
"You've got to be careful around this place not to get overconfident," said Rossi, who opens on the outside of row three.
"Everything is trending in the right direction. I was happy in the traffic. I think we've got it and we'll pray it's all right on Sunday."
The annual IndyCar classic was moved from its usual late May date due to COVID-19 concerns that delayed the start of the season until June and will prevent spectators from attending an event that draws nearly 400,000 fans annually.
"Ultimately I don't think this year is going to be much different than the past couple of years," Rossi said. "It's going to come down to the last 10 laps again."
Andretti, the grandson of 1969 winner Mario Andretti, was among the slowest when it came to fast laps, 28th at 221.314 mph, but quite pleased with what he learned about his car and himself.
"Today the goal was to put myself in the most uncomfortable circumstances possible," Andretti said. "I'm not planning on leading 200 laps. It was as uncomfortable as I thought it would be.
"When it's not going right, that's the pressure."
Andretti, a 2006 rookie runner-up in his best showing of 14 Indy 500 starts, spent time on small details so they are not surprises on Sunday.
"We went through about 10-15 different things, not necessarily big things," Andretti said. "We found out stuff the car doesn't like. We're going to work on not having to deal with it. I'd rather do that today than Sunday."
Andretti's pole win Sunday raised hope that his family "curse" in a half-century of chasing a second Indy win might end on Sunday.
"It has been a fairy tale," Andretti said. "It feels like a win even though it was just qualifying.
"I'm in a good place mentally. We just have to execute on a lot of levels to win this race."
- Alonso faces challenge -
Two-time Formula One world champion Fernando Alonso will start in the middle of row nine. The Spaniard is trying to complete a Triple Crown that also includes the 24 Hours of Le Mans and F1 Monaco Grand Prix.
"We made another step forward. Quite happy with the results," Alonso said of a session where he was 23rd overall at 222.680 mph.
Alonso was confident he could move up quickly from deep in the field, with teammates O'Ward and US rookie Oliver Askew, fifth Friday at 224.128 mph, showing the car has the speed he needs.
"Starting at the back is even more challenging, but we love these things," Alonso said. "It's going to be a challenge for everyone... We need to rely on strategy and luck."
Beside him on the inside of row nine is defending champion Simon Pagenaud. The Frenchman was 14th at 223.419 mph.
"We're going to have to be aggressive right away," Pagenaud said. "I need clean air to move forward. If I can't get clean air I won't go anywhere."