Susie Wolff says her first test in the FW36 was a day of learning as she had to adapt to the new 2014 power units.
Although the Williams test driver is no stranger to a Formula 1 car, Wednesday's outing in Barcelona was her first time driving under the new regulations.
As such the 31-year-old had to adjust to a new way of driving.
Wolff, who caused a red flag when she spun into the gravel at Turn 10, completed 55 laps and finished fifth on the timesheets.
Her 1:27.280 was 2.409s slower than Pastor Maldonado's P1 time in the Lotus.
"This was my first opportunity to drive the FW36 and I learnt a lot about how to drive these new look cars which are very different to previous seasons," Wolff revealed.
"With last year's car the harder you pushed the faster you went, but now you have to manage certain elements a lot more.
"The cars also have a lot more torque which was a steep learning curve, and this caught me out at the beginning of the session.
"Overall it was a productive day for the team and we worked very well together to quickly complete our planned aero and mechanical evaluations.
"I was then able to get some good mileage under my belt to understand the characteristics of the car and how to get the most out of this new style of power unit."