Senna: Difficult to judge who is quickest

Heidfeld and Senna  completed 149 laps combined over the two days of testing, as the Indian outfit prepares for the second FIA Formula E season.

Senna finished seventh on the first day and improved on Tuesday to end testing third quickest, 0.750s behind leader Lucas di Grassi.

"Testing went very well and we're getting closer to the ballpark of where we would like the car to be," the Brazillian said.

"We tried a few control and electronic things and validating the work we are doing in terms of reliability for the car.

"There are faster laps to come, but we are going in the right direction," he added.

Heidfeld, on the other hand, finished just behind his teammate on both the days with eighth and fourth positions.

On the second day, the German and the Brazillian were separated by just four thousandths of a second.

"We managed to improve the balance through the day," Heidfeld said.

"Looking at the lap times, I think it's obvious that the circuit is a bit quicker now that there's more and more rubber on it.

"It's still very difficult to judge who is the most competitive at this stage. As a team, we are trying lots of things and validating results on both cars."

Senna echoed his teammate and stated that it is 'difficult' to see which team will be the quickest in the first race in Beijing.

"The two ABT drivers have achieved very quick laps, of course, but we won't see where everyone is until everyone gets some full 200kW laps in," he said.

The Mahindra team also tested a different type of wheel rim, which they stated was for 'improved aero and stiffness'.

The ABT Schaeffler Audi Sport team drivers were quickest both the days, with Daniel Abt taking charge on the first day while di Grassi finished on top on the second day.