Timo Glock kept Toyota at the top of the times in testing at Jerez, showing that the Japanese squad's car is also fast in the dry.
Glock had been quickest in yesterday's rain-hit session, and the German showed impressive pace once again by topping the times with a best lap of 1:19.814.
He was the only driver to lap the Spanish circuit in less than 80 seconds.
"That was a productive day," said Glock. "This morning we were again a bit unlucky with the conditions, which made the race simulation quite tough. But it was useful to find out when to change to slick tyres and our pace wasn't bad.
"Then we got some dry running for the rest of the day. We did a lot of set-up work and late on we did some shorter runs to make it through the programme. We've made it through a lot of miles over these two days and we're making useful progress."
Felipe Massa returned to work after skipping yesterday's test, the Ferrari driver covering a massive 134 laps on his way to the second fastest time of the day, over four tenths of a second behind Glock.
Massa was joined by seven-time world champion Michael Schumacher, who observed the session from the pit wall.
Renault's Fernando Alonso was the busiest man on track today, completing 152 laps onboard the R29, which moved away from the bottom of the times to finish in third position on the timesheets.
"Today was a very productive day as I managed to complete 152 laps which gave us lots of useful data," said the Spaniard. "At this stage of the season it's important to have as much time in the car as possible to get used to the new rules such as the moveable wings and the KERS system and so I'm happy to have done so much today.
"Everyday we keep learning new things and I'm feeling more and more comfortable in the car. Hopefully tomorrow we can have another dry day to build on the work we did today."
Heikki Kovalainen was again the man in charge of testing duties for McLaren, the Finn posting the fourth quickest time ahead of Adrian Sutil, who replaced Force India teammate Giancarlo Fisichella at the wheel of the new VJM02.
Sutil, who had completed the shakedown of the car last week, managed 63 laps and wound up less than a tenth of a second behind Kovalainen.
"I think today was a good day," said Sutil. "It was important to get into the car again and to get confident. The car was OK; there is definitely potential, and we were able to do more mileage and find some reliability in the afternoon.
"In the morning we had a little problem but we could fix it over lunch and start to do our programme. The tyres dominate a lot and the different compounds react differently: you have to find a good set up and get them to work and that is where we are concentrated now.
"We had some instability on the rear and oversteer, but we will see tomorrow. We are at least more reliable and can try and get some real mileage on the car now."
Australian Mark Webber was back in action with Red Bull as he continued working on getting fully fit for the start of the season. Webber finished in front of BMW Sauber's Robert Kubica, seventh fastest today.
"Overall it was a good day," Kubica said. "We were able to make up some of the time we lost yesterday when rain meant we had to change our schedule. I started on extreme wet tyres, changed to wet tyres and finally drove slick tyres.
"Together with the various different set-up solutions I tried that helped me get an even better feeling for the car."
Nico Rosberg was slowest for Williams, 1.5 seconds off the pace.
Pos Driver Team Time Laps 1. Glock Toyota (B) 1:19.814 141 2. Massa Ferrari (B) 1:20.238 134 3. Alonso Renault (B) 1:20.296 152 4. Kovalainen McLaren-Mercedes (B) 1:20.535 85 5. Sutil Force India-Mercedes (B) 1:20.621 63 6. Webber Red Bull-Renault (B) 1:21.021 98 7. Kubica BMW-Sauber (B) 1:21.069 98 8. Rosberg Williams-Toyota (B) 1:21.412 125 All Timing Unofficial