Sebastian Vettel said Red Bull had work to do to improve his car's reliability after he retired early from the Australian Grand Prix in a frustrating start to his world title defence on Sunday. The German four-time defending world champion, along with Mercedes' 2008 winner Lewis Hamilton both only lasted a handful of laps in the season-opening race won by Nico Rosberg in a Mercedes. Formula One has switched to quieter, turbocharged 1.6-litre V6 engines this year with hybrid components and Vettel has been struggling to make the adjustments in his car. Vettel said ahead of the Australian race he would have been happy just to finish at Albert Park after severe problems at pre-season testing. But he was left flummoxed by Sunday's loss of power. "People were passing me -- I didn't understand," Vettel told reporters. "It is difficult to say when exactly but in the second formation lap I realised I had no power. "I tried to recover but it didn't happen. There is a bit to work on in terms of reliability. I have wasted a lot of points in this race but it's a long season." Vettel's retirement ended his record-equalling run of nine straight race wins and put him on the back foot in his quest to equal Michael Schumacher's sequence of five consecutive world titles. He said: "We can fix the situation but the question is how soon. But once the package comes together we know we will be quick." Pole-sitter Hamilton said he knew straight away that something was wrong with his Mercedes, which suffered a misfiring cylinder. "My start didn't feel great today and I had a lot less power than usual when pulling away, so it was obvious immediately that something was wrong," he said. "It looks like we only had five cylinders firing and, while I wanted to keep going, we had to play safe and save the engine. "It's unfortunate but that's racing and we will recover from this. We have a great car and engine, and the pace was really strong today as Nico Rosberg clearly showed. "Big congratulations to him and the team for achieving the win, it's a fantastic result for us." Source: AFP