Ryan Hunter-Reay has ended second practice fastest ahead of the Honda Indy 200 at Mid-Ohio, with light rain interrupting the 45-minute session.
Proceedings got underway in overcast but dry conditions, much like the opening practice session earlier in the day, with the times immediately tumbling below Simon Pagenaud’s benchmark from the first session.
Josef Newgarden ended the session second for Penske, with the Chevrolet-powered outfit’s dominance from the first session under threat by the likes of Andretti Autosport and Chip Ganassi Racing.
Championship leader Scott Dixon managed P3 for Chip Ganassi Racing, with the four-time champion improving somewhat from his benchmark earlier in the day during practice one.
Reigning champion Pagenaud was a relatively competitive fourth for Penske, with the Frenchman initially trading the top spot with team-mate Newgarden throughout the early stages of the session.
Roughly halfway through proceedings light rain struck the 2.258-mile road course, creating a tricky situation where it was almost too damp for dry tyres and yet way too dry for wet tyres.
Initially the whole field returned to the safety of the pits, with dry weather forecast for the remainder of the weekend and therefore nothing to be gained by the teams by running in the inclement weather conditions.
However, as the rain slowly eased several drivers braved the elements on dry weather tyres, including Graham Rahal and Mikhail Aleshin, before the rest of the field followed to create a busy end to the session.
Alexander Rossi rounded out the top five for Andretti Herta Autosport, ahead of 2014 champion Will Power.
The Penske racer endured a far from perfect session, running extensively wide at Turn 2 and skipping through the gravel.
Fortunately Power was able to keep his car away from the barriers and rejoin the action, as the session progressed without any major delays.
Marco Andretti was P7 for Andretti Autosport, ahead of Graham Rahal as Honda power continued to jostle within the top ten with rival manufacturer Chevrolet.
Helio Castroneves and James Hinchcliffe rounded out the top ten, with both drivers momentarily rising to the top throughout the busy session.
Reigning Indianapolis 500 winner Takuma Sato was the only Andretti Autosport racer outside the top ten in P11, ahead of rookie Ed Jones.
Further down the order IndyCar veteran Tony Kanaan could only manage P18, ahead of former Formula 1 racer Esteban Gutierrez in P19.
