Daniel Ricciardo has endured more frustration as world champions Red Bull struggle to get up to speed for Formula One’s season-opening Australian Grand Prix.

Young Australian newcomer Ricciardo took over from teammate and four-time world champion Sebastian Vettel for the final two days of a four-day F1 pre-season testing round at Bahrain’s Sakhir circuit.

But there were more furrowed brows in the camp as issues with the Red Bull car, with their Renault engines, meant he could complete only 28 laps on Friday then just 15 on Saturday.

Both days they were well off the pace and there is only one testing week left from Thursday in Bahrain before the Australian Grand Prix in three weeks.

“In all honesty it wasn’t a great day today, I guess we still need more time,” said Ricciardo after Saturday’s closing session ended prematurely.

“We have four more days coming up and hopefully we can maximise them.

“At this stage we just need laps…”

Ricciardo placed seventh in the time sheets, better than his ninth on Friday but a full six seconds off the pace set by Germany’s Nico Rosberg in his Mercedes.

Rosberg managed to go a second faster than his teammate Lewis Hamilton a day earlier, outpacing Jenson Button’s Mclaren and Kimi Raikkonen in a Ferrari.

Red Bull had previously struggled badly in that first four-day test in Jerez last month when they failed to drive even 100km in total.

And Vettel had only limited success when driving the first two days in Bahrain.

On the first day he got off to a slow start with over four hours of work being done on the RB10 car in the garage before the German emerged and his work was curtailed when smoke poured out the back of the car.

Things went a little better the following day when Vettel was able to run 58 laps, though again well off the pace in seventh.

Red Bull race engineering co-ordinator Andy Damerum indicated the problems faced in Bahrain were different to those experienced in Jerez and involved some very late night work between Ricciardo’s two sessions.

“Because of its nature it means we have to take the car apart,” he said on Friday.

“These issues are of course frustrating but this was unrelated to the others so it’s just a case of tackling each issue as it appears.