Helio Castroneves led the way for Penske on the first day of collective IndyCar testing in 2016 as he set a new unofficial lap record at Phoenix International Raceway.
The entire IndyCar grid was invited by INDYCAR to Phoenix for a two-day test ahead of April's race, which will be the first for the series at the Arizona oval since 2005.
Castroneves picked up where Penske left off for much of 2015 by posting the fastest time of the day in the first session, lapping in 19.5858 seconds with an average speed of 187.850 mph.
The Brazilian's time topped the existing lap record set by IndyCar legend Arie Luyendyk back in 1996 of 19.608 seconds (183.599 mph). However, testing does not count towards official records.
Castroneves was pleased with Penske's start to testing on Friday as he racked up 116 laps in total across the day and night-time sessions.
"We were able to run in both temperature [conditions], which was OK," Castroneves said.
"Obviously, earlier today in the day conditions, we were focusing on speed and the Hitachi car was really dialled in. This evening, we were able to work more on the race pace, and everything seems to be going in the right direction.
"We're looking strong and looking good, but we're still learning about this updated Chevy aero kit. Looking forward to tomorrow and learning even more."
Castroneves was joined at the top of the timesheets by Penske teammate Will Power, who also bettered Luyendyk's record with a best lap time of 19.5931 seconds.
Marco Andretti was the leading driving running the Honda aero kit, ending the day third for Andretti Autosport ahead of 2015 series champion Scott Dixon.
Ed Carpenter put his oval nous to good use en route to finishing the day fifth ahead of teammate Josef Newgarden, while James Hinchcliffe's official return went well as he ended up seventh overall. Carlos Munoz finished eighth, while Charlie Kimball and Tony Kanaan rounded out the top 10.
You can see the full results from the opening day of testing at PIR here.
