What to keep an eye out for at Barcelona testing
Testing is a particularly hard thing to judge. It's almost impossible to come up with an accurate pecking order, even by the third and final test, but there are a couple of things to keep an eye out for over the next few days which might offer at least some clue as to what's what.
Ferrari - are they truly a title contender?
Whilst one can never write off the prancing horse, particularly after their chart topping times in Jerez, you'd be best advised to take their pace with a pinch of salt.
Whilst it looks certain that the SF15-T is a step ahead of its predecessor, closing the mammoth gap to Mercedes would be an almighty feat.
Barcelona should offer a better overall picture of where they stand. The circuit is a good indicator of outright performance as it features a good mix of low to high speed corners and straights.
Rivals, particularly Mercedes which admitted to taking it easy in Jerez, will be looking to ramp up their efforts as they look for competitive lap times, rather than a focus on reliability.
McLaren-Honda - another stuttering start?
It's important for McLaren and Honda to get some more running under their belts. Jerez wasn't a complete disaster, but it certainly wasn't plain sailing.
The partnership completed just 79 laps as numerous power unit niggles interrupted their testing programme. They will both be looking to get out on track as early as possible and for as long as possible over the next four days.
A filming day on Monday should help. Honda have brought various updates to its engine since Jerez and they were ran this week ahead of the test, giving the team at least some time to iron out any major issues which might have arisen.
They're not worried yet, but that might not be the case if they don't manage at least double their Jerez lap tally in Barcelona.
Force India - an updated VJM07?
Force India are already struggling and the season hasn't even begun. The Silverstone based team has yet to debut its 2015 car and doesn't plan to any time soon.
The team has chosen to run its old car at this test with Mercedes reserve Pascal Wehrlein behind the wheel - a result of money troubles? - for two of the days.
The question is whether the outfit will run the same specification VJM07 which finished the 2014 season, or whether they'll bolt on some new bits destined for the VJM08. The livery launch car did at least have a 2015-style nose.
Noses - a trip to the plastic surgen...
Speaking of noses, we can expect to see a few changes. McLaren and Ferrari opted for the longer nose, whilst the majority have tried to go as short as possible. In theory, shorter is better as it allows more airflow underneath the car.
Mercedes have admitted they'll go slimmer and shorter at some point, but in order to meet the crash tests, they had to fit a chunkier than desired nose.
That could be the case for both McLaren and Ferrari, therefore resulting in a complete change ahead of Melbourne, unless they've found a benefit to having the tip much further forward.
Sauber - reborn?
No, we're not talking about the yellow go-faster stripe they've added to their nose for the Barcelona test - though it's nice to see a car embracing something other than grey - we're talking about their performance.
The Swiss team languished at the bottom last year and failed to score a single point. That's simply not good enough and the team will be hoping to score regularly this year.
They got off to a flying start in Jerez and topped the times on day three. Is that pace a true indication of how far ahead the C34 is compared to the C33? Probably not.
Some have called it a glory run, others believe the team have made a step forward, though not a significant one. Barcelona should, like Ferrari, be a more accurate indicator of their performance.
Lap time - records broken?
Last season saw one qualifying lap record broken, proving that the new cars are no slouches. 2015 looks likely to see many more broken if Kimi Raikkonen's Jerez time is anything to go by.
The Finn managed a 1:20.841, which was almost 2.5 seconds quicker than the fastest lap posted in Jerez last year. Whilst you can't say that's definite proof the cars are significantly quicker, it's a promising sign.
Barcelona will give a more accurate picture of how much quicker the cars are - and they should be. The engines have been improved, the cars have been developed through 2014 and that knowledge has been carried over to the 2015 cars.
Lewis Hamilton took pole with a 1:25.232 at the same circuit last year. Nico Rosberg was quickest during pre-season testing in 2013 - the last time F1 tested at the circuit - and posted a 1:20.130 in V8 machinery. We can expect this years cars to get closer to Rosberg's time which would be a huge improvement. Time will certainly tell...