Red Bull team principal Christian Horner revealed after Sebastian Vettel's season-opening victory in Melbourne that the team did not have KERS on its RB7s from Saturday onward.
There was speculation after Vettel took pole position that the team was planning to use an innovative "start-only" KERS, but Horner told British TV that the team had been concerned with reliability on its conventional system and merely opted not to run it.
"We haven't had KERS on at all this weekend," said Horner. "We didn't want to tell anybody, but looking at the start ... It didn't look like we needed it.
"We were a bit nervous about telling everybody before the race. We ran it on Friday and we weren't happy with the reliability, we felt it was a potential risk, so we took it off both cars and didn't race it at all this weekend."
"We made a decision with the KERS, he added. "It's quite a complex system, it's an interesting technology, but Adrian [Newey] being Adrian would not compromise the car around the system so it has had to fit into his aero shape and that's presented some bigger challenges. But the guys have done a fantastic job in Milton Keynes and testimony to their hard work that we've turned out and been reliable and dominated the race."
Horner said that he was delighted with Vettel's dominant throughout the Australian GP weekend culminating in a crushing victory for the world champion over the rest of the field.
"It's been a fantastic day for Sebastian and the team to start this championship, on different tires with the regulation changes we've had," he said. "He was dominant yesterday and totally dominant today as well. It's a shame for Mark [Webber], but a great team result."
Webber finished a distant fifth, having employed a three-stop strategy to Vettel's two. The Australian was outpaced all weekend by his teammate, and pulled off the track at the end of the pitlane as soon as he finished the race.
"Well, it's a very unusual gap to see such a big difference between the two guys," said Horner of Webber's pace compared to Vettel. "We need to go through things with a fine toothcomb and understand where those differences are.
"Mark's performance today – he was very hard on the tires – that created more degradation. We need to find out if there's something perhaps in the car that is contributing to that. We couldn't find it yesterday, but we'll certainly have a very, very good look before Malaysia."