Team Penske’s Will Power demonstrated the impressive form that helped the Aussie to close the 2013 season with a win at Fontana by topping Wednesday’s test at Sonoma Raceway in his Verizon-sponsored No. 12 Chevy.

Power was among 10 Chevy-powered entries and three Honda drivers to take part in the single-day run on the winding 2.3-mile road course which was nominated by the GM brand as one of its official Manufacturer tests.

“We’re definitely on the right track,” Power told RACER. “At the end of last year, we were lacking a little bit on road and street courses, and we’ve made good gains on improving over the off-season. And it was good to get back in the car; other than some testing at Sebring, I haven’t really been in a car on a road course since last season, so it was good to get out, get a lot of laps and get into a rhythm. It was a good day.”

Times were unofficial, and with cool temperatures, a general lack of grip, drivers making runs on old and new tires and different engine specifications, it’s hard to draw any major conclusions—positive or negative—based on what took place.

The best lap times hovered in the 1:18.1 range for most of the day, but a few late runs on new Firestone rubber dropped the leaders into the high 1:17 bracket, with Power and Target Chip Ganassi Racing’s Scott Dixon in the 1.17.8 to 1.17.9 vicinity.

The defending IndyCar Series champion was quick from the outset, logging more miles for the Ganassi team as they forge a new relationship with Chevy after spending the past two seasons with Honda.

Of the pleasant surprises on Wednesday, the pace of KVSH Racing and new driver Sebastien Bourdais turned a few heads. The team readily admits it was at a deficit on road and street course pace in 2013, yet Bourdais and engineer Olivier Boisson had the Mistic-sponsored No. 11 Chevy atop the times throughout the day before settling in with the third-fastest time of 1:18.1.

Schmidt Peterson Motorsport’s Simon Pagenaud was the first of the Honda runners, placing fourth with Honda Performance Development’s new twin-turbo V6. Pagenaud followed his countryman by clocking a 1:18.2, just ahead of Team Penske’s Helio Castroneves in fifth (1:18.4).

Ganassi’s Tony Kanaan (1:18.4) and Charlie Kimball (1:18.5) were sixth and seventh, SPM’s Mikhail Aleshin, using one of Honda’s 2013-spec single-turbo units, was eighth (1:18.6), Ed Carpenter Racing’s Mike Conway (1:18. 6) and Ganassi’s Ryan Briscoe (1:18.8) rounded out the top-10.

A.J. Foyt Racing’s Takuma Sato (1:18.8), Team Penske’s Juan Montoya (1:18.9) and new KV/AFS Racing signing Sebastian Saavedra (1:19.0) completed the time sheet on his first day of testing since the 2013 ended.

Panther Racing and driver Carlos Huertas were included on the test day entry list, but they did not appear.

The general impression from Sonoma was that Chevy, with two years of twin-turbo experience, has produced a stout powerplant built to the more open 2014 engine regulations. Honda, which spent the last two years on single-turbo induction, has been catching up at a rapid pace, and worked steadily on engine mapping throughout the day.

Some of Chevy’s cars demonstrated impressive shift-cut strategies, for example, as Power and a few others rocketed through their upshifts with a hint of seamless transition—a noticeable improvement from 2013. By the end of the day, Pagenaud was also onto a similar, if not identical shift-cut strategy. Both manufacturers will continue to find gains through the electronics to exploit as much speed, power and traction as possible ahead of the Marc 30 season opener in St. Petersburg.