Di Grassi won the inaugural Beijing ePrix last year after Nico Prost and Nick Heidfeld tangled while fighting for the lead.

But the ABT Schaeffler Audi Sport driver is adamant he cannot be considered a favourite for the upcoming race, despite his team's strong pre-season showing.

“We did a good pre-season, and we have a good level of specification for a complex technical package. Are we favourites? No, I wouldn’t go that far, there are too many unknowns in the first races,” di Grassi told Motorsport.com.

Di Grassi and his rivals will find an altered track in Beijing this weekend, compared to its original 2014 specification.

The removal of the first chicane and the modification of the other two will see noticeable changes to the layout, which runs around the perimeter roads of the 2008 "Bird's Nest" Olympic stadium.

“With regard to the track, we have one less chicane this year and the other chicanes are a bit tighter, so we don’t know the real effect on lap times, but probably it will be quicker because the cars will be faster in season two,” he said.

“At Donington we were 1.5 seconds better with our own drivetrain.

"But there is much that is unknown and needs to be understood in race conditions. The engineers and the drivers will earn their money this weekend for sure.”

Energy efficiency crucial

Di Grassi, like many in the Formula E paddock, believes that races and ultimately the title will be won by the most efficient package on the grid.

“We have two ways of how we will evaluate Beijing," he said. "One is true performance, which is qualifying. So in qualifying you go maximum power, you go as quick as you can but it doesn’t matter how much you consume in energy.

"The race will be a different story. This is when the efficiencies of the new tech will really come to the front. Then we will only know who is ahead in terms of efficiency and this will be the interesting part.

"Race mode, of course, will only be seen and studied after the ePrix this weekend. These new parameters will be interesting to see. It will be close again I’m sure.”

Thermal management comes to the forefront

Di Grassi insists that, with the increase of battery power available up from 150 to 170kW in race trim, managing temperatures will be more important than it used to be in season one.

“If the battery has the same cooling as last year which I expect, then it will heat more," di Grassi explained. "So the thermal heat will be more and it will be even tougher to manage. It will be interesting, especially in Malaysia.

"The worst will be a safety car because then it gets counter-intuitive. You’d expect the battery temperature to drop, yes? It’s actually the opposite.

"If you have just enough safety car laps, you can do the rest of the stint flat out. So if you save enough energy, then the rest of the laps are completely flat out and the battery heats up a lot.

"So, if there is a little bit of safety car, it is bad for the battery and motor temperature in the long-view, and if you have a lot of safety car or Full Course Yellow laps, then you don’t reach enough energy, you go flat out but you don’t reach the 28kW, so it’s tough for the temperature management.”