Gary Anderson's testing verdict

It's always difficult to draw any great conclusions from testing, the first test of a new season especially so.

Most teams will have been concentrating simply on getting in some decent-length runs and some will have gone for a little bit of glory to help attract some much-needed sponsorship.

I'm going to run through the eight teams that participated in fastest laptime order.

FERRARI - A much better start

Ferrari looks to be in much better shape than it was last year. Its laptimes in general were impressive at Jerez.

Both drivers require a car that has a very positive and consistent front end, and both appear to like the handling characteristics of the new Ferrari SF15-T.

This is always a major asset when it comes to car set-up and development direction, so overall it was a very encouraging test for Ferrari.

SAUBER - No harm in chasing headlines

Sauber appears to be benefiting from the improved performance of the Ferrari power unit.

As I mentioned at the start, some teams can go into testing seeking a few headlines (I've done it myself at times!) and no doubt Sauber is doing a similar thing.

It needs to attract some sponsorship, and what better way to do that than to turn in some competitive laptimes and make sure that you end all four days either first or second?

But the car does look consistent and much better than last year. Felipe Nasr and Marcus Ericsson extracting some performance from the C34 will give everyone at Hinwil a lot of motivation.

MERCEDES - Getting on with the job

Mercedes simply got its head down and focused on the test programme, paying very little attention to what was going on up and down the pitlane.

That said, at the end of day one I suspect someone on the Mercedes pitwall will have dusted down their spare stopwatch to take a look at Ferrari. Even Nico Rosberg admitted Ferrari's performance was "eye-opening".

It's always difficult to go slow in a fast car. Normally the best way to do this is to run more fuel, which means that the car can be driven with the same level of aggression but without delivering the laptime.

Is that what Mercedes is doing or is Ferrari going to give it a hard time this year? Is Mercedes sandbagging?

Let's wait until the next test at Barcelona to see how things unfold, but it's worth nothing that the fastest Mercedes laptime was set on the medium tyre rather than the softs used by Kimi Raikkonen to set the overall quickest time.

WILLIAMS - Some 2014 weak points cured

Williams appears to have made a little progress. The 2014 car was very good on corner entry with a very positive front end, but it always looked to me like the rear was on edge.

This year's car has carried over that positive front end and the rear is better than it was.

One of the biggest advantages Williams had last year was its top speed, as the car was always fast in a straight line.

The Williams did trip the main speed trap in equal first place at Jerez, with a mark of 307.6km/h - matching Mercedes.

The problem Williams had last year was that on some circuits the car just couldn't generate the downforce of some other cars.

The Barcelona test will be a better indication of how much of a gain has been made as the Spanish Grand Prix venue is a circuit at which laptime and downforce go hand in hand.

TORO ROSSO - An underdog that could star

The team that was once Minardi has once again shown that a relatively small operation can put together a car that runs and can be understood from the word go, even though the Renault engine problem meant that it had to make regular visits to the pits for checks.

It has what you might call a very young driver line-up (although even that seems to be an understatement) so it would be easy to hide behind that.

But team principal Franz Tost is a racer and he and technical director James Key seem to have a clear idea of how to get the best out of the team.

Franz is talking about fifth in the championship and why not? The car looks promising and was more reliable than the Red Bull.

With a development plan in place pre-Melbourne, and Renault promising an engine that can be run properly for the next test, this could prove to be a small team doing a big-team job.

LOTUS - Confidence returning

Lotus was a bit late getting up and running. But the team had a much better start to testing this season than last year, when the car didn't even make it to the first test.

Lotus lost a lot of good people in the build-up to 2014 and the team was shell-shocked. It's taken a bit of reorganisation to get the people left working efficiently, but there's a lot of skill and experience there so the team is ready to work its way back up the grid.

The Mercedes engine is a huge step forward, but the car also looks a lot better. Last year's car was very inconsistent and it just didn't do the same thing twice.

Once you have a car like that it spooks the driver and he loses confidence. Hopefully after getting into this year's car their confidence will be returning.

RED BULL - Dabbling isn't enough

So why have you had to read all the way to this point before I mentioned the team that had so many dominant seasons and thought it owned F1?

When you compare the current Red Bull to Toro Rosso, you could argue that the junior team has done a competent job while the main team has potentially dropped the ball.

Adrian Newey has lost his true commitment to the F1 side of things and he has shown he is disillusioned with the way the regulations are going, so has got involved with other projects.

Yes, he is still part of Red Bull Racing, but the thing about F1 is that you can't just be a visitor. You either have to be in it 100 per cent or not at all. There's no room for dabbling.

Vettel moving to Ferrari is another blow, as the team was more or less set up around him. Daniel Ricciardo did a great job last year but what will happen this year if Red Bull doesn't perform? It could disintegrate.

Barcelona will be a big test. The Renault engine held things back at Jerez, and as Renault's works team there will be no excuses if things don't get better.

If Red Bull doesn't improve, the cracks will start to show.

McLAREN - A terrible start

McLaren is difficult to judge after a terrible test.

Everyone keeps harping on about how the McLaren and Honda relationship is building. They keep telling us how the car is so innovative that they expected all these problems.

All that is rubbish. What they really would have expected was to put the car out on the track and do at least 100 laps a day.

So McLaren will be going home from Jerez very, very disappointed because it seems like a case of problem after problem and nobody has got on top of the engine yet. The Barcelona tests could very easily be the same.

That said, the car does look pretty good on the track. But when you are not using all the power then most cars look good...

Hopefully, I will be proved wrong because we want the McLaren-Honda fighting at the front. Barcelona will hopefully let us know where it stands.

With four days of testing down and eight more to go, my general feeling is that Mercedes will have some closer company at the front of the field this year.

But I still don't really have a clue who it's going to be.