Every race weekend on the NTT IndyCar season, there is one thing or another that challenges the drivers and teams.

Sometimes it’s the weather, other times it’s a new track, or one engine manufacturer seems to have an edge on the other.

This weekend at the Honda Indy Grand Prix of Alabama, the problem is a little closer to the surface — the racing surface, that is. After the first day of practice at Barber Motorsports Park, figuring out the difference between the Firestone red and black compounds was the big topic of conversation.

Easily explained, the balance on the car between the two types of tires is drastically different, and at least for this session, the blacks were producing the faster laps instead of the other way around, which is usually the case.

James Hinchcliffe posted the top lap of the day around the 2.3-mile, 17-turn course, driving his No. 5 Arrow Schmidt Peterson Motorsports Honda to a time of one minute, 8.994 seconds while on the red compound. He admitted that was really only because he didn’t really run his best laps on the blacks.

“(Friday) afternoon was very weird,” Hinchcliffe said. “I made a couple of mistakes on my black lap. I don’t think that we were as high up before switching to reds as we would have liked or where we were capable of being, and then we threw on the reds, and the balance just fell apart, and the car was — I’ve never been so unhappy with the balance of my race car. It’s interesting because last year at Barber the balance between the black and the red Firestones was actually quite small for us. This year that was not the case.

“Everybody has got a bit of homework to do for qualifying (Saturday).”

The whole issue might just come down to science. With four different support series laying down different types of rubber, the racing surface itself is just a little bit different in terms of grip.

“In theory (our tire) should be the same, so it could be a function of track conditions, the various different rubbers on the track,” he said. “Obviously there’s a few more supporting series here than they’ve had in the past, at least different ones. So, it’s a combination of a lot of things. But obviously it caught everybody out. At a track with a bunch of long fast corners, normally the reds were going to be significantly faster, and most guys didn’t improve their times.”

Despite the challenges, Hinchcliffe is very happy with how his day turned out Friday. Finding speed has been difficult through the first two races of the season, which has led disappointing starting positions of ninth and 15th at St. Pete and Circuit of The Americas, respective.

“We were (als0) P3 in the first practice, so that made us feel good just knowing that rolling off the truck the car was pretty strong,” Hinchcliffe said.”I think that’s big. That’s been maybe not our strength the first two races of the season. We kind of had to dig ourselves out of holes the first two weekends, which I think I actually did a pretty decent job at. But if you can start with a good car and just sort of have to fine tune it, it makes it that much easier.”

Following up his historic win at COTA, Colton Herta was second quick on the day in 1:09.0084. Herta, who became the youngest winner in IndyCar history in Texas two weeks ago, has lived through a bit of a whirlwind since then, with plenty of travel and media-related responsibilities. He did find time to get into a simulator, though, and felt like the gains they found there translated well to Barber.

“I think we had a pretty good baseline coming here,Herta, who celebrated his 19th birthday on March 30, said. “We worked a lot on the sim. I know a lot of the guys were in the sim, so we got in there Tuesday after COTA, and we found some good stuff, and that translated into our starting setup a little bit. So, we already had a baseline on what we felt comfortable with, and moving forward, just little things, spring changes, maybe a little bit in the damping, but kind of general changes, not too big a changes.”

The rest of the Top 10 in practice was definitely a mixed bag of drivers and teams, and might hold a key to what could be an interesting qualifying session. Dale Coyne Racing teammates Santino Ferrucci and Sebastien Bourdais were third and fourth, respectively, followed by Alexander Rossi, Ryan Hunter-Reay, Spencer Pigot, Felix Rosenqvist, Pato O’Ward and Marco Andretti.

All told, there were six different teams in the mix, including four rookies. Eight of the Top 10 have Honda power.

Practice 3 goes off at 10:45 a.m. CDT, with qualifying beginning at 3 p.m.