The Mid Wales also went fourth fastest during day two, just 0.830 seconds pacesetter and Davies' former teammate, Scott Redding, to show he is really getting to grips with his new Ducati.
The riders were greeted with a cold and windy Motorland Aragon on the first day, which Ducati and Yamaha riders line up on the grid.
Davies, 34, was even forced to wait a couple of hours before leaving the pit lane with his Panigale V4RS to freezing wind and low asphalt temperatures.
Once the The Go Eleven Team rider, from Presteigne, was eventually able to get out on track, he focused on the geometry and balance of the bike.
During the afternoon, the track was considerably faster, so much so that the times got closer to those of last year's races.
And at the end of the day, Davies went fastest, breaking the wall of 1.50 with the best lap of 1.49.878.
Davies said: "We tried a different balance on the bike and we found an interesting direction.
"The feedback was quite positive when we compared the bike to the one I had used in the past two years here in Aragon.
"The best thing about today is that I feel quite comfortable with every tyre and I felt good on the bike.
"It was a good step forward compared to Barcelona test, a couple of weeks ago."
Good weather and warm temperatures returned for day two of testing, which saw most riders posting quicker lap times.
Davies was again riding below the wall of 1.50 at the end of the first morning session, which meant he was able to focus on working with the soft tyres during the afternoon.
But the feeling in the qualifying tyre was still not great, which has given the team something to focus before round one, which also takes place at Aragon in May ???.
The final two days of testing will take place from May 5-6, on the Navarra track, in Spain, which will be making its debut on the World Superbike calendar.
Davies said: "It was busy, a very busy day. We had a lot to evaluate and quite a few changes on the bike, some positive some less, but overall I think we have a really clear picture on what's working.
"I feel like I have a bike I can race now. If we need to race tomorrow, I feel I would be ready.
"That's really positive and I was comfortable, which is the most important thing.
"I am happy with the way all the guys have been working. Now let's focus on the next test at Navarra."