INDIANAPOLIS – If there’s one thing known following the final practice prior to the 102nd Indianapolis 500 presented by PennGrade Motor Oil, it’s that no one knows for sure what is going to happen in Sunday’s iconic race.

Miller Lite Carb Day at Indianapolis Motor Speedway featured the traditional one-hour practice for Verizon IndyCar Series competitors – the last chance for the 33 drivers and teams to zero in on the ideal car setup for race day. Tony Kanaan, the 2013 Indy 500 winner, led the session with a lap of 227.791 mph in the No. 14 ABC Supply AJ Foyt Racing Chevrolet.

“I think this is the closest that we're going to get as far as weather for Sunday, so we tried to optimize that and run in the heat conditions and see what are we going to do,” Kanaan said. “But really, if you haven't figured it out by today, you're in trouble.”

INDIANAPOLIS 500 PRESENTED BY PENNGRADE MOTOR OIL: Miller Lite Carb Day practice results; Combined practice results

With the 2018 Indy car featuring the universal aero kit in use for the first time on a superspeedway oval, teams used every minute of the final practice to gather data in the sunny and warm conditions. The forecast is similar for race day, with temperatures expected in the low 90s.

A total of 1,273 laps were run on the 2.5-mile oval on Friday – an increase of more than 300 laps from Carb Day practice a year ago.

“I remember back in the days when we had to save the engine and you couldn't do more than 10 laps (on Carb Day) to save it for the race,” said Kanaan, the 21st-year driver who will make his 17th Indy 500 start and record 289th straight start in an Indy car race on Sunday. “Nowadays, the engines are so good, Chevy does such a great job, that you can run full power all the way through. So then you tell the engineers that, we ran three sets of tires, almost 50 laps.”

Scott Dixon, the 2008 Indy 500 winner, was second on the Carb Day practice speed chart with a lap of 225.684 mph in the No. 9 PNC Bank Chip Ganassi Racing Honda.

“I don’t really know if today told us too much about what the race will bring in the PNC Bank car,” Dixon said. “It’s really warm today and we think it could be even warmer on race day. The track temp was way up there today as well. I’m not really sure what you can learn from the times today.

“Overall, the car felt good and we were comfortable. You just never know exactly what you’re going to have until you get into the race.”

Fifteen drivers turned 40 laps or more in the practice, led by Graham Rahal’s 51 laps in the No. 15 United Rentals Honda for Rahal Letterman Lanigan Racing. Ed Carpenter, who will lead the field to the green flag as the pole sitter on Sunday, was 14th fastest in the No. 20 Ed Carpenter Racing Fuzzy’s Vodka Chevrolet (223.219 mph).

Danica Patrick, making this year’s Indianapolis 500 the final race of her epic career, ran only 15 laps, as an electrical issue forced her Ed Carpenter Racing crew to hustle the No. 13 GoDaddy Chevrolet back to its Gasoline Alley garage for repairs. Patrick still wound up eighth on the speed chart with a lap of 223.653 mph.

“We had a little bit of an electrical issue, but our team was able to get me back out there before practice was over,” said Patrick, who will make her eighth Indy 500 start on Sunday with a best finish of third place in 2009 to date. “At the end of the day, these are things you’re actually glad for, because if this had happened Sunday, we would have been done. I’m glad to get the issues out of the way early on.

“Overall, today felt good. We made some changes when I went out the second time, and I’m feeling good about starting seventh on Sunday.”

All 33 cars are now locked away in their garages as crews make final changes in anticipation of race day. Drivers will be kept busy Saturday at IMS with a public autograph session (9 a.m. ET) and the traditional public drivers meeting starting at 10:25 a.m. (streaming live on RaceControl.IndyCar.com). They will all then ride in the IPL 500 Festival Parade in downtown Indianapolis.

The 102nd running of the Indianapolis 500 airs live at 11 a.m. Sunday on ABC and the Advance Auto Parts INDYCAR Radio Network. Tickets remain available at IMS.com.