|© AP Photo/Miguel Angel Morenatti
Reliability issues that dogged Lewis Hamilton and Jenson Button as McLaren teammates last season made an early appearance in preseason testing in southern Spain on Tuesday.
As Button completed his third lap around the Jerez circuit, McLaren's redesigned MP4-28 spluttered to a halt just ten minutes into testing with suspected fuel delivery problems.
The 2009 world champion helped team workers to cover the car before a truck arrived to transport it back to the pits.
Button, who was able to return in the afternoon session, said the team was concerned there could be a recurrence of the fuel pickup problem that caused Hamilton to abandon the Abu Dhabi Grand Prix last year after leading for 20 laps.
Although Hamilton did not drive for his new team Mercedes on Tuesday, there was a more spectacular car failure for the Briton's teammate Nico Rosberg as a flash of flames followed by smoke erupted from the rear of his Silver Arrow.
The session was interrupted while the car was towed off the track.
The problem which sidelined Rosberg for the rest of the day was attributed to a major wiring fault, the team said on its Twitter account. "After identifying the cause of the problem we will not be running again today whilst parts are modified ready for tomorrow," the team said. "The part which requires modification is the wiring."
Hamilton is due to be at the wheel of Mercedes' new car on Wednesday.
Last season Hamilton and Button between them won seven out of 20 races -- the same number as championship winners Red Bull -- but McLaren still only came third overall because of a lack of reliability. Not ending races in the points was less of a problem for Fernando Alonso's Ferrari, which came second overall despite only clinching three wins.
Christian Horner, Red Bull team principal, said last year had taught him how vital an ingredient consistency was. "We delivered when it mattered," Horner said. "You've got to make sure you get the maximum from each race weekend of the 19 available this season."
Horner said mechanical reliability needed to combine with driver consistency for results to be maximized. He insisted that Sebastian Vettel would not receive preferential treatment as has often been rumoured in the past, after the young German won three world championships back-to-back while his teammate Mark Webber languished further down the standings.
Horner said until one driver began to show a clear winning trend compared to the other, the 36-year-old Australian would be given the same options as Vettel.
"Mark has been with team seven years, he knows he'll get equal treatment, that's why he's chosen to stay with us. What happens on the circuit will determine which way our championship bid will tilt," Horner said.
Webber said he anticipated it would be a tough season, with rival teams pushing Red Bull harder than last year, when they ended 60 points clear of Ferrari.
He said the team needed to adjust the car's tendency to understeer when going around bends.
"We're not having a Grand Prix race tomorrow, thank God, so we'll work hard," he said. "We're going to be pushed hard. The team have been through a lot in the last four or five years so we are very strong mentally to deal with some ups and downs, as we proved last year."
Although Button lost five hours of practice at Jerez, he was able to come back and set the fastest time of the first day of practice at the hilly, sinuous circuit, beating second-place Webber by nearly a full second.
"This morning was boring really, I was sat in the office, sorry, sat in my motor-home all morning. I was glad to get the problems out of the way early," Button said. Last season McLaren also started well, with Button and Hamilton driving what most observers felt was the fastest car until the rest of the pack caught up.
Ferrari driver Felipe Massa said his car felt much more predictable this season compared to last. He said last year the team had taken far too long trying to understand why the car didn't respond as anticipated.
The Brazilian driver said he had "suffered a lot" last year on Pirelli tyres. On this year's Pirellis, Massa said they felt "much more grippy, softer" than last year's equivalents. "Jerez is a circuit that degrades tyres a lot, so you can't necessarily take it as a benchmark for the whole season, but I was happy with them."
Massa, who was sixth fastest, said the times looked similar to last year's, with Button fastest. "I'm not sure how much fuel he was carrying, but yes, it's a phenomenally fast time he's set," Massa said.
On his debut outing, Marussia's British driver Max Chilton set a time nearly six seconds slower than Button's, mainly because he lost control, spun the rear of his car and crashed into barriers at high speed.
The 21-year-old emerged from the cockpit unhurt, having showered nearby photographers with broken carbon fibre chips as he skidded before halting. The Russian-owned team said it needed to figure out what caused the crash before testing could resume.
||Paul di Resta
||Giedo van der Garde