Team Penske and Ed Carpenter Racing ruled the opening round of practice on Tuesday at the Indianapolis Motor Speedway.

Will Power posted the fastest lap of 229.745 mph in his Verizon 5G Chevrolet — just a tick quicker than teammate Simon Pagenaud’s best of 229.703 mph in his Menard’s Chevy.

“All the big speeds came from big tows,” said last year’s Indy 500 victor. “What IndyCar wanted Firestone to do with the tire is exactly what it has done, which is help that front work off the corner so you can follow closer; and you’ve just obviously got to get your car to work around that.

“It’s kind of hard to judge the true speeds of cars right now by themselves. You don’t know what aero configuration people are running, whether they’re doing qualifying sims or they’re in race trim,” Power continued. “We don’t know where we stack up, honestly, as far as true speed.”

But Carpenter’s crew won the day by posting the best speed without a tow from another car. Ed Jones, in the Scuderia Corsa Chevy who is driving all the road races for ECR, clocked a lap of 224.542 mph, which was easily the best of that category.

Carpenter, last year’s pole-sitter and race runner-up, was fifth fastest among the non-towers with a lap of 223.135 mph in the Preferred Freezer Chevy after running the third quickest tow lap of 228.653 mph.

It was a busy seven hours as all 36 cars made it onto the track and completed nearly 3,000 laps,with the only incident Colton Herta’s spin on the warmup lane in Turn 2.

Temperatures were in the ’60s all day — some 20 degrees cooler than is forecast for qualifying this weekend.

Besides Carpenter, six other drivers topped 228 mph:three-time Indy winner Helio Castroneves, Herta, Sebastian Bourdais, Zach Veach, Alex Rossi, and Marco Andretti.

Pato O’Ward was stymied by mechanical problems in his bid to complete his rookie test, so he’l be given 40 minutes on Wednesday morning before official practice begins.

PRACTICE 1