Mercedes pair Lewis Hamilton and Nico Rosberg showed flashes of pace in Friday’s second free practice in Japan before heavy rain effectively washed out much of the afternoon session.
Red Bull’s Daniil Kvyat topped the timesheets at a soaking Suzuka, clocking one minute, 48.277 seconds with Rosberg 0.023 back and reigning world champion Hamilton a further half-a-second slower.
Daniel Ricciardo clocked the fourth fastest time with Singapore winner Sebastian Vettel steering his Ferrari to the fifth-quickest lap.
Rain had created havoc in the morning practice, when only 12 drivers completed a timed lap as they struggled to keep control of their aqua-planing cars.
Mercedes, looking to fix a mysterious loss of pace in Singapore last weekend, shot out to the quickest times in the second session, before Kvyat backed up an impressive early display by edging ahead of Rosberg.
But just as things began hotting up, the rain returned to send the cars back to their garages and when Hamilton finally emerged on wet tyres, he was warned over the radio “be mindful of the rivers,” so soggy were the conditions.
With memories of Frenchman Jules Bianchi’s fatal crash at a wet Suzuka last year certain to make Sunday’s race an emotional one, drivers were anxious to avoid taking any risks in the treacherous conditions.
Hamilton, who suffered his first retirement in over a year last week but still boasts a 41-point championship lead with six races left, expressed frustration that Friday had turned into little more than an exercise in data analysis.
“You don’t want to take too many risks, damaging the car,” he told Sky Sports. “Today we were just practising starts and getting a couple of laps in – but there wasn’t really an awful lot to learn.”
Looking forward to Saturday’s qualifying, the Briton added: “I hope it’s dry. Today is a shame for the fans. They’ve been sitting in the rain and not seeing many cars go round. It must be a bit boring for them.