JEREZ, Spain (AP) -- Ferrari's Fernando Alonso and Red Bull newcomer Daniel Ricciardo both sputtered to a halt during their first day of Formula One preseason testing on Thursday.
Alonso's car stopped after 26 laps just before the Jerez track's Ayrton Senna chicane. His Spanish fans cheered him on from the stands as he was ferried back to the pitlane.
Ricciardo only made it halfway around the circuit before his RB10 spouted smoke. Both drivers went back out after team mechanics had tended to their vehicles in the garage.
Ricciardo is debuting for Red Bull after four-time defending F1 champion Sebastian Vettel was limited to just 11 laps over the first two days of testing. Vettel's run on day two was cut short when engine-maker Renault reported a malfunction in Red Bull's motor.
"Slow progress this morning as we try to put together all the pieces in Jerez," Red Bull said on Twitter.
Niko Hulkenberg was the third driver to be stranded after his Force India stalled on his seventh lap.
All teams are struggling to get their cars race ready after F1 made a sweeping revision of the rulebook that included a shift to a turbo engine and integrating more sophisticated energy recovery systems.
Testing concludes in southern Spain on Friday, followed by two more tests in Bahrain. The season opens with the Australian Grand Prix on March 16.