Chevrolet continued to dominate practice for the Angie's List Grand Prix of Indianapolis, with Penske's Helio Castroneves the latest to shine on the 2.439-mile, 14-turn road course situated in the in-field of the famed Indianapolis Motor Speedway.
Castroneves - who is making his 300th start in the Verizon IndyCar Series championship this weekend - set a time of 1:10.3756s (124.765mph) on his final lap of the circuit to put him 0.0257s ahead of KVSH Racing's Sebastien Bourdais, who had been the fastest man in the first practice of the weekend 24 hours earlier on Thursday afternoon.
CLICK: Full practice 3 times from Indianapolis Motor Speedway
Castroneves' lap was almost a third of a second that Scott Dixon's practice 2 time which had been the fastest so far. However, it is still somewhat off Simon Pagenaud's 2014 track qualifying record of 1:09.6716s, despite the addition this year of the new bespoke aero kit bodywork components to improve speed and grip.
"It's interesting. I mean, we're testing the new aero package," agreed Pagenaud, who went on to win the inaugural IMS road race and clearly has hopes of making it two-for-two this weekend. "It's just a matter of understanding what the car needs. So far so good. I think the Penske cars are in pretty good shape.
"The heat is going to be interesting this weekend, and the weather as well,: he added. "We don't know, it might be raining. Anything can happen. Certainly quite slippery in eight and nine. There's a lot of grass on the track."
If the rain stays away then there's still a good chance that the track record will fall in qualifying later on Friday, when the teams will break out the red-wall soft option tyres that give them extra grip for faster time trial laps.
Pagenaud was third fastest on Friday morning, finishing just ahead of his Penske team mate Will Power. Dixon was fifth fastest in the Chip Ganassi Racing #9, a quarter of a second faster than the fourth and final member of the Penske line-up, reigning series champion Will Power who was sixth fastest.
Graham Rahal was the fastest member of the Honda-powered contingent for the second session in a row. He was notably outspoken at the end of Thursday about the need for Honda to improve its aero and engine offerings as the manufacturer continues to find the same sort of raw speed and power as Chevrolet is managing on both street/road and oval circuits.
Rahal was eighth fastest on Friday morning and 0.6649s slower than Castroneves in the session. He was the only Honda-powered car in the top ten, with AJ Foyt Racing's Takuma Sato just missing out in 11th place.
In all, 15 of the 25 cars in action at IMS on Friday managed to record laps which were within one second of the top time. Not among that number were any of the Andretti Autosport drivers, who all struggled to find pace and balance again. Ryan Hunter-Reay ended up in 16th place and was 1.0451s off Castroneves' benchmark time, with Marco Andretti, Carlos Munoz and team new boy Justin Wilson grouped together in 21st, 22nd and 23rd places ahead of a brace of Dale Coyne Racing crs driven by Carlos Huertas and Francesco Dracone.
In total, the slowest seven cars were all Honda-powered. The lowest of the Chevrolet runners was JR Hildebrand, returning to action for the first time in a year (and for the first time in 21 months on a road/street course) in a third CFH Racing car alongside the team's regular drivers Josef Newgarden and Luca Filippi.
There were no significant incidents during the 45-minute session, but there appeared to be some bad blood between team mates Power and Montoya with Montoya fuming as he exited his car on pit lane following an on-track spat with the Australian through turns 7, 8, 9 and 10. Montoya subsequently appeared to utilise hand signals from the pit wall to convey his emphatic displeasure at Power's driving in the session.
Qualifying is set to get underway at 3pm local time (8pm BST) and will follow the usual three-round elimination format for street and road course races, with the first round split into two groups to help alleviate problems with traffic and blocking.
Teams will then have one final half-hour warm-up session on Saturday morning before the Angie's List Grand Prix of Indianapolis gets the green flag in the afternoon at 3.50pm (8.50pm BST).
See full practice 3 times from Indianapolis Motor Speedway