Speaking after a Chevy manufacturer test day at PIR that involved the four Team Penske entries and ECR’s pair, IndyCar’s only owner/driver told Motorsport.com: “In race downforce we were pulling about 4.2g, so I think we were eventually up to 4.5g. Pretty big.”

Referring to the kink in the back stretch that was reconfigured in August 2011, Carpenter said: “I don’t know if it’s the dogleg being straightened out but the radius has changed because it’s more banked, less flat than it was.

“But actually I don’t think that made as big of a difference [to the physicality of the track] as the resurfacing. Phoenix is now the next-smoothest track to Indy, and it’s high grip. It reminds me of Iowa before it got bumpy.

“That’s actually going to present its own challenge because there won’t be much separation between the cars; everyone’s going to be pretty good at figuring it out.”

Carpenter, who along with co-owners Tony George and Stuart Reed, recently resumed control of the team he merged with Sarah Fisher Hartman’s squad in the fall of 2014, said that with only six cars at the track, he hadn’t had much chance to practice running in traffic.

“There was never a time when we had all six of us out there,” he said. “Penske had three – maybe all four at one point, but not for more than about 10 laps. I ran behind Simon [Pagenaud of Penske] for a couple runs, then I was behind him for a couple runs, but I didn’t see anyone do a full-tank to empty outing.

“I think we were all using the opportunity to have a clean track and work on things that will be harder to do at the open test with the whole field there.”

Improved aero kit

For 2016, Carpenter has retained Josef Newgarden who enjoyed a breakout season in 2015, scoring his first two IndyCar wins. Carpenter, who will drive the second ECR entry for the oval races only, said they both noted improvements Chevrolet has made to the IndyCar aero kits in the off-season. However, he remained naturally reticent about details.

“We started the day on the original short-course kit, and then went to the new kit, and yeah, it was different. I think we’d feel the difference more at other places than here, but it’s obviously better. I’m not going to tell you how much better! But yeah, it’s an improvement… although what we had before wasn’t bad, either.

“But I’m happy with the gains Chevy have made with the parts we’ve seen so far.”

Carpenter was similarly cagey about how he expects Honda to have responded following IndyCar’s off-season decision – under Rule 9.3 – to allow HPD to work on its road/street/short-oval in more areas than Chevrolet. Some Honda loyalists have sounded bullishly optimistic in recent weeks but Carpenter is more skeptical.

“I haven’t jumped to those conclusions,” he said. “I…think there are people in the Honda camp who talk a lot! Whether it’s from confidence or lack of confidence, I don’t know.

“I’m withholding judgment until I see them on track together, but what I will say is that I have ton of belief in Chevrolet. I believe in their approach, their processes, and the route they’ve taken over the last two or three years of aero kit development.

“We’ll see. I think the kit designs are naturally morphing together a little bit, so who comes out on top is more down to the implementation. I actually think that’s where Chevy had the big advantage last year. I don’t think on their best days, the difference in performance capacity [between Honda and Chevrolet kits] was all that major.

“But anyway, we’ll know a little bit more from testing, but won’t know the true situation until we get to [the first round] in St. Petersburg.”