It wasn't the start to Formula One testing in Barcelona that Daniel Ricciardo had hoped for.
But the Aussie's remaining optimistic he'll get some solid miles in before it wraps up.
Ricciardo's RB13 stopped on track twice on the opening day.
A sensor alarm on a crank shaft forced the morning stoppage before the car was parked in the afternoon when the battery energy charger went kaput.
If he's frustrated, then Dan's not showing it.
“I’m not worried,” said Ricciardo. “I guess, especially from the engine side, we are playing it a bit safe and making sure that we don’t do damage on day one. That is the main thing.
"But I think for now, the last two hours we got some good running and hopefully that continues for the rest of the test. Hopefully Max [Verstappen] tomorrow does 200 laps.”
Engine supplier Renault is yet to crank up the engine's performance to the max, but Ricciardo says Red Bull's early pace is encouraging.
He ended the day 6th after racking up 50 laps in the afternoon session.
At the top of the time sheet Mercedes picked up where it left off last season with the fastest car.
Lewis Hamilton shared time behind the wheel with new team-mate Valtteri Bottas, bettering Sebastian Vettel's Ferrari by 0.113 seconds.
Fernando Alonso's day was one to forget with the Spanish star seeing none of the track because of an oil system problem.
"It's definitely not a perfect start of the winter testing," said Alonso.
"We are disappointed, we are sad to arrive to the first day and not be able to run. We know and are aware of the time we lost today, we have four days for each driver before the world championship starts and now one day is gone."
"So I have three days to prepare a world championship. It's not an ideal situation."