How far ahead is Mercedes?

Heading into the Spanish Grand Prix weekend, the talk was all about Mercedes being reeled in by the rest. Instead it effortlessly bagged its fourth one-two in five races, which but for a split in a small rubber tube covering a spark plug in Australia would have been its fifth.

Looking at those one-twos more closely, one of the reasons Lewis Hamilton has beaten Nico Rosberg on all four occasions is revealed in the fuel-use graphic that appears during the race.

Hamilton seems to use less fuel than his team-mate, so how he can do that and still beat him is a bit of a head-scratcher. It would be easy simply to say he's just faster, but there's more to it than that.

He appears to have learned a consistent way of driving and using less fuel while still doing the required lap time. That means he is able to start the race with less fuel.

Looking at the graphic, it appears to be an average of 3.5kg less fuel over the race distance. So on a pure weight-versus-laptime calculation, this is worth 0.1 seconds per lap. That's 6.6s over the Spanish GP. If both drivers and their respective cars have identical performance, that gives Hamilton an advantage of almost seven seconds over the race distance.

Mercedes is racking up the points, but its advantage is being amplified by the fact that everyone else is jostling for position behind. In Australia, it was the McLarens of Kevin Magnussen and Jenson Button on the podium; in Malaysia Sebastian Vettel; in Bahrain Sergio Perez and then Fernando Alonso in China.

Hamilton uses less fuel than Rosberg during the races © LAT

With Daniel Ricciardo third in Spain, there is no clear rival chasing Mercedes down. Everyone in Brackley, Brixworth and Stuttgart must be rubbing their hands in glee at the situation.

Mercedes' overall performance has been very impressive. Using my performance statistics, which take the fastest lap set by each team on a grand prix weekend and convert it into a percentage of the outright fastest, this is how the teams average out over the first five races of 2014.

Mercedes
Red Bull    +0.948%
Ferrari     +1.197%
Williams    +1.289%
McLaren     +1.623%
Force India +1.779%
Toro Rosso  +2.085%
Sauber      +2.833%
Lotus       +2.906%
Marussia    +4.578%
Caterham    +5.287%

By way of comparison, this is how the teams stacked up over the 2013 season.

Red Bull
Mercedes    +0.070%
Lotus       +0.472%
Ferrari     +0.552%
McLaren     +1.102%
Force India +1.190%
Sauber      +1.291%
Toro Rosso  +1.294%
Williams    +1.911%
Caterham    +3.762%
Marussia    +3.987%

If you look at the two sets of statistics and compare the relative performance, you could say Mercedes has just about stood still and that it's the others that have fallen away. Some of them dramatically.

One thing that confuses me a little about Mercedes' race performance in Barcelona is that this is the first grand prix of 2014 where they haven't had the fastest race lap.

Rosberg had the means, motive and opportunity. In the latter stages of the race he was chasing down his team-mate. He was on the softer of the two tyres and he was reasonably low on fuel, so all the stars were aligned.

But it didn't happen and the honour went to Vettel on lap 55. Yes, his tyres were a little bit fresher than Rosberg's were on lap 51 when the Spanish GP runner-up set his personal best, but with the performance margin that Mercedes had, it should have been enough for fastest lap.

Ricciardo saw the Mercedes duo disappear into the distance © LAT

Ricciardo in the other Red Bull started third and ended up third. He was around 49 seconds behind both Hamilton and Rosberg, and all three did two stops.

This is an average of a 0.74s per lap advantage for Mercedes, which is not far away from what it was in qualifying.

On the other hand, Vettel came from 15th on the grid, did a three-stop race and ended up 76 seconds behind the leading two.

Take away 22 seconds for that extra stop and you get a 54s deficit, or an average of 0.82s per lap slower than the winner.

Any advantage he got from that extra set of tyres would have been negated by traffic, so why was he able to get the fastest lap in a car that on average was knocking on the door of being a second a lap slower than the winning car?

Does this mean that Vettel has finally got his head around how to drive this year's car? He's a driver that really does try to exploit a car's DNA - last year with the blown diffuser system he was without doubt the one that exploited it the most.

When I go out on the circuit during practice sessions, I'm still seeing a car being driven to exploit the extra rear grip that last year's cars had when you got the throttle open.

Vettel has had a fairly troubled start to the season and not had the consistency of running that a driver needs in order to adapt his driving style. In contrast, Ricciardo had never really driven a car with a good blown diffuser system and when I watch him on track he is very precise and consistent.

His Red Bull looks the class of the field, very stable, and as he builds up steering angle on corner entry he can just lean on the car; you can see the car build up roll, but not break away.

The others, including the Mercedes, all look that bit more nervous and one end or the other will ultimately give up.

Red Bull did enjoy a step in engine performance from Renault, but as engines are a lot less important in Monaco perhaps at last we will see the car's true performance.

As for the others, the statistics tell the whole story. Williams is the only team that has made any real progress and the rest have gone backwards relative to Mercedes.

Lotus was really off the pace at the start of the season, so that hurts its average, but even in China it was at +1.243 per cent and in Spain that increased to +2.027 per cent off Mercedes. I think this shows that grid position can be confusing - in the end it is ultimate pace that's important.

I always used to look at the grid average being separated by 0.1s per position. In Barcelona, Button - who was eighth on the grid - would have been roughly 0.8s off pole, but was actually 2.1s behind Hamilton. This is a lifetime in F1.

Ferrari finished a lap down in Spain © LAT

As for Ferrari, which should be mixing it with the best for race wins, Barcelona was a reality check. New team principal Marco Mattiacci probably thought that after Alonso's third place in China this F1 lark was easy. What a difference a few weeks can make.

The team said after China that the result was a surprise, and the same will be said about sixth last weekend.

Looking at the car out on circuit, every corner of every lap is a new experience. It just doesn't look like it has any consistency, and the rear end is critical.

This is a problem that needs to be addressed if they are ever to get the drivers confident enough to allow them to push nearer the limit.

But Monaco in two weeks is a very different track. Rosberg won there last year, so will Mercedes dominate again? With all that extra torque from this year's power unit, these cars will take a bit of driving there, but after all, that's why these guys get paid the big bucks.

When we last had turbos, the Brabham-BMWs were reputed to have something like 1400bhp. Actually, they couldn't measure it as the dyno would only run to 1000hp, but whatever they had, Piquet was able to leave black marks from the chicane all the way to Tabac.

It's going to be fun watching trackside. I wonder who can leave the longest black marks this time around?

If you have a question that you would like Gary Anderson to answer in his regular feature where he takes reader questions ahead of a Grand Prix, Tweet using #askgaryF1 and he will choose a selection to answer.