Melbourne, Australia ( - After months of preparation and testing, 11 teams and 22 drivers are ready to get the 2014 Formula One season underway with this weekend's Australian Grand Prix.

There's a lot of uncertainty for teams entering the season-opener in Melbourne, and it's anyone's guess as to who will do well and who won't in Sunday's 58-lap race. This season is featuring one of the biggest set of rule changes in the history of F1, especially the technical regulations.

This year's cars are equipped with a new 1.6-liter, V6 turbocharged power unit (engine), which relies heavily on hybrid technology. There's also major alterations to the exterior designs of the cars. Aerodynamic changes have been made to reduce downforce.

Practice took place at Melbourne's Albert Park Circuit on Friday, with Fernando Alonso from Ferrari leading the way in the opening session and Mercedes' Lewis Hamilton topping the time charts in the second practice.

During P1, Alonso turned a lap around this 5.303-kilometer (3.3-mile), 16-turn circuit in 1 minute, 31.840 seconds, which was a half-second quicker than his closest competitor, McLaren's Jenson Button, who has won the Australian GP in three of the last five years. Alonso was third in P2, behind the Mercedes duo of Hamilton and Nico Rosberg.

"On the first Friday of the season, there's always a bit more tension," Alonso said. "It's the start of a new championship, and there is the feeling of general expectation to see how things we worked on during the winter are functioning. Overall, this was a positive day for us, and even if there was an element of nervousness because of the complexity introduced by the new technical regulations, everything went well. The team did a super job, and we had no problems."

Hamilton, though, had a troubling session in P1, as he stopped on track just after a single lap. The 2008 F1 world champion encountered a faulty oil pressure sensor, which caused a precautionary engine shutdown in his Mercedes. Hamilton bounced back nicely in P2, completing 37 laps. His best lap was clocked in 1:29.625 37.

"It really was a day of two halves [Friday]," Hamilton said. "While it was disappointing to not get any track time this morning, these little hiccups are going to happen with the new cars, and we'll have to get used to that. It felt like I was on the back foot from there, but then we got up to pace quite quickly in P2 and found the balance relatively fast.

"I feel quite comfortable in the car, so overall, it's a positive start, but we need to look at the data now and understand where we are. We got a nice foundation for the weekend in the second session, so hopefully we can build on that in P3 [Saturday] and then see where we are in qualifying."

After a frustrating past few months in pre-season testing in Jerez, Spain and Sakhir, Bahrain, four-time reigning world champion Sebastian Vettel and Red Bull, winner of the F1 constructors' title the past four years, had much better results in practice for the Australian GP than it did in testing.

Vettel did not get on track in P1 until nearly one-hour had expired. He recorded just 10 laps during the session, with his best lap in 1:32.793, good for seventh-place. In P2, Vettel significantly increased his track time with 41 laps. He finished fourth in that session (1:30.381).

"In a way, it's a relief today, the fact that we were running, and we didn't have any problems, and the balance was good and the performance looked alright," Vettel said. "In the end, Friday times are not worth a lot, but it's better to be close to the top rather than somewhere towards the back, so I'm very happy with that.

"We will do what we can to prepare for tomorrow and Sunday, but let's see where we are then. The most important thing is that we finish."

Vettel started on the pole and finished third in last year's Australian GP. Kimi Raikkonen, who is back with Ferrari this season, is the defending race winner.

Vettel's new teammate, Daniel Ricciardo, who is the only Australian competing in this year's race, was not too shabby in practice, finishing fifth in P1 and sixth in P2. Ricciardo is taking over Mark Webber's seat at Red Bull following Webber's retirement at the end of last season.

"I think we have to be pretty positive with where we ended up today," Ricciardo said. "Let's see if it's the same story after qualifying tomorrow, but for today, we're pleased."

Series: Formula One. Date: Sunday, March 16. Race: Australian Grand Prix. Site: Albert Park Circuit. Track: 3.3-mile (5.303-kilometer), 16-turn temporary street circuit. Start Time: 2 a.m. ET. Laps: 58. Miles: 191.110 (307.574 km). 2013 Winner: Kimi Raikkonen. Television: NBC Sports Network.