Renault e.dams has become the first Formula E team to test its season-three powertrain on track.
Teams manufacturing their own powertrains have 15 test days before official pre-season testing commences in August.
Senior manager of Renault e.dams Jean-Paul Driot confirmed it had completed a brace of three-day runs, making it the first team hit the track with its season-three car.
"We are testing new components and you cannot compare anything because it's very difficult to evaluate," he told Autosport.
"We are testing to see how it works, but before that we have to evaluate and confirm the efficiency and the reliability.
"We have to homologate before June 1. We are in a busy second part of the season and at the same time having a development test, and June 1 is only five weeks away."
That puts Renault considerably ahead of its current rivals, while the incoming Jaguar squad is understood to be close to kicking off its programme.
Senior figures from seven of the current participating teams confirmed to Autosport they had not yet started testing.
Most expect to do so in the next month, although Dragon Racing - which is developing a powertrain for the first time - and Abt Audi Sport are not concerned by the prospect of having to wait until after the June 1 homologation deadline.
Teams are not required to test before that deadline, but it does mean they cannot alter their motor, gearbox and inverter designs should they encounter problems thereafter.
Autosport understands Venturi's new powertrain will not have a four-speed gearbox like the current VM200-FE-01, but its exact configuration is unknown, while Mahindra has already confirmed it is switching from McLaren to Magneti Marelli for its M3Electro motor supply.
NEXTEV TCR has confirmed it will retain a twin-motor set-up.
Team Aguri, the only outfit not registered as a manufacturer, is currently evaluating an ownership bid and has not yet concluded a powertrain supply deal, so is not under the same pressure to start testing for the 2016/17 campaign.
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