Lucas di Grassi was fastest in the opening practice session in Mexico City, although the reigning champion has another grid penalty hanging over him for this weekend’s race.

The Audi Sport ABT Schaeffler driver was one of four to complete a 200kW lap of the Mexico City circuit alongside Venturi’s Edoardo Mortara, Andretti’s Antonio Felix da Costa and NIO’s Oliver Turvey.

Another inverter change for di Grassi means he will be receiving a 10-place grid penalty for the ePrix, and extra experience at 200kW running may prove the difference between starting from the midfield or the back of the grid for the Brazilian.

Mortara was second fastest, over a third of a second off di Grassi’s time, with Techeetah’s championship leader Jean-Eric Vergne setting the pace for the drivers who only completed laps at 170kW, almost half a second back.

Although he did not run at 200kW, Vergne’s best lap was significantly faster than last year’s pole time, showing the progress the teams have made like-for-like in a season.

A late lap by Jaguar’s Mitch Evans put him in fourth, ahead of Alex Lynn (DS Virgin), Jose Maria Lopez (Dragon), Felix Rosenqvist (Mahindra) and di Grassi’s team-mate Daniel Abt.

Lynn topped the times briefly, with team-mate Sam Bird, who went ninth fastest, was one of the first to test the limits of the circuit.

Renault e.dams’ Sebastien Buemi was 10th fastest, having spent most of the session in the top three.

Andretti’s Tom Blomqvist and NIO’s Luca Fillipi were the slowest two drivers, both enduring sessions punctuated by off-track moments and technical problems.

The FIA’s introduction of a track limits zone on the run to Turn 1 meant there was no repeat of drivers spinning on the grass as often seen last year, although the dusty track surface meant grip was still at a minimum.

An 8am local start time meant both air and track temperatures were below 20°C, meaning heat management was not an issue, although the drivers had to face the blinding morning sun.