Ryan Hunter-Reay

MADISON, Illinois – Preparations for the Bommarito Auto Group 500 presented by Axalta & Valvoline are involving some drastically changing weather conditions.

Verizon IndyCar Series drivers waited out a rain delay Friday before they could get on track to practice for Saturday night’s race at Gateway Motorsports Park. The temperature struggled to get into the 70s Friday afternoon, but is expected to soar past 95 degrees by Saturday afternoon. The green flag for the 248-lap race is expected to fly at 7:40 p.m. CT, right about the time of sunset.

That’s expected to give a slight early advantage for the four Andretti Autosport drivers – Alexander Rossi, Ryan Hunter-Reay, Marco Andretti and Zach Veach – who tested at the 1.25-mile oval near St. Louis in hot conditions on July 18.

“Conditions now are cooler than what we had at our test, so we’ll a have a little bit more grip (on Friday), potentially,” Hunter-Reay said. “Race conditions tomorrow will be similar to our test. I think we can pull forward what we found at the test and apply it. Trying to get the front to work in traffic will be our big hurdle.”

Rossi, who won Sunday’s ABC Supply 500 at Pocono Raceway, is now 29 points behind Verizon IndyCar Series leader Scott Dixon with three races – Gateway, Portland International Raceway on Sept. 2 and Sonoma Raceway on Sept. 16 – remaining on the 2018 schedule.

“When we were here, it was only the four of us (at Andretti Autosport), so there wasn't really much group running that we did,” Rossi said. “But I would imagine it would be kind of similar roadblocks that we run into that we have seen this year, and it's just kind of waiting on the front if you do have a run, and hopefully you can keep the front end under you.”

One thing the Andretti drivers did learn from the July test was the cars lacked grip in the front end, especially in traffic.

“The challenge is going to try to keep the front end under you in traffic” Hunter-Reay said. “It washes out and you lose that run and then take that whole lap to get back under the gearbox of the guy going into Turn 1. That would be a limiting factor for us. Hopefully we can find a way around that.”

It will be the first race at Gateway with the universal aero kit introduced this season, meaning all but the Andretti drivers are inexperienced with the car's characteristics on the egg-shaped oval, which features a different radius in Turns 1-2 from that of Turns 3-4.

“We should be pretty good,” said Graham Rahal, whose Rahal Letterman Lanigan Racing team didn’t test the new kit at Gateway. “The hopes are high, the expectations are high, and there are three weeks left to get a win this year. We’d be pretty disappointed to leave this season without a victory. We’re pretty determined to make it happen."

Rain forced the Friday schedule to be condensed. A scheduled 60-minute practice began shortly after 4:30 p.m. ET. Qualifying is scheduled for 6:30 p.m. ET and will stream live on RaceControl.IndyCar.com, youtube.com/indycar and the INDYCAR Mobile app. A final 60-minute practice is scheduled for 9 p.m. ET and will stream on the same outlets.

Live race coverage is scheduled to begin at 8 p.m. ET Saturday on NBCSN and the Advance Auto Parts INDYCAR Radio Network.