The weakness Mercedes must fix for 2018

Lewis Hamilton won't have wanted to win it with ninth place in the Mexican Grand Prix, but he's a very worthy four-time world champion.

After all, it's not about one race - it's the whole season that counts and he has more wins than anyone else, so well done to him.

But while Hamilton has shown how well he can rise to the occasion, a look at the championship points shows that, in reality, Ferrari threw the championship away.

If Ferrari and Sebastian Vettel had continued scoring as they did in the first half of the season rather than driving into each other or breaking down, it doesn't necessarily mean Hamilton wouldn't have been champion - but it would have been a dogfight to the chequered flag in Abu Dhabi.

2017 F1 title race

How the top six have scored through the season

The Mercedes has been a bit of a 'diva' at some tracks, but it's a rocketship at others. On average it's been the fastest car, but extracting the speed consistently is like finding hen's teeth.

This is where Hamilton has excelled, finding the solution and bringing home the results. That's what earned him his fourth title.

It's probably that little bit easier to fight a driver who is racing for another team because you have your own development path, which just has to be stronger than the opposition.

When you're fighting your own team-mate you both have the same development path, so you never get that little step that means you can get a few races where you are better.

In Mexico, Ferrari showed it has a better all-round car than Mercedes

The one thing that really stood out to me during the Mexican GP was that the Mercedes is not as good in traffic as the Ferrari. Admittedly Hamilton had some diffuser damage, but we have seen the same scenario at previous races this season and this is something that Mercedes needs to pay attention to for next year.

If Red Bull and Ferrari can start the season as strong as they are currently, then next year there could very easily be six cars fighting all season long, so having the car that's best in traffic will pay dividends.

I said in my Austin column that we had not yet seen the true performance of the current Ferrari with its new developments. It normally takes a clean weekend before you can get the data and driver input that allows a team to understand how to get the best from any update. This is exactly what we saw when Mercedes brought a major upgrade to Sepang and couldn't get on top of it straight away.

In Mexico, at least in qualifying and with Vettel behind the wheel, Ferrari showed it has a better all-round car than Mercedes.

And just to confirm that Ferrari has once again got its mojo back, Vettel did the fastest race lap on lap 69 of 71 with 36-lap-old ultra-softs.

This also must show Pirelli that it needs to look at its tyre compounds. This is the softest tyre in its range and in reality those tyres should be hanging off the rims by about lap 10.

In qualifying, it was Max Verstappen's Red Bull snapping at Vettel's heels. The Red Bull just seems to have more grip and is able to use the kerbs in a more advantageous way.

By that I mean the Red Bulls don't bounce around as much as the Ferrari or Mercedes; they just seem to absorb the kerb impacts so the driver can actually plan how to use it to get the best lap time, as opposed to just hanging on for dear life hoping that they can get on the throttle without losing rear grip.

I always say there is no such thing as luck, but I think Verstappen's results this season might prove that there is.

Earlier in the season he was plagued with reliability problems but in Mexico, when Renault-engined cars were dropping out right, left and centre, his held together and he scored his third win.

There's more to come from this young guy and if you're into betting, a little flutter on him winning next year's world championship wouldn't go amiss.

As Verstappen said himself, he was cruising, but that was only possible because of the first-lap-complex shenanigans between him, Vettel and Hamilton.

They all touched each other somewhere in that opening sequence of corners, but Verstappen got away with it whereas Vettel had to pit for a new front wing and tyres. Hamilton had to pit after a slow lap with a puncture. The title rivals rejoining 19th and 20th meant in reality the drivers' championship was won there and then.

A little flutter on Verstappen winning next year's world championship wouldn't go amiss

It was a bit silly that Hamilton and even the Mercedes team thought Vettel had hit him on purpose. Why would he do that intentionally when he's the one that needed the points from this race to retain any hope of taking the championship?

Hamilton needs to take his fair share of the responsibility. Putting his car on the outside of two cars that were already banging into each other was just a touch risky. But given his strong championship position after a great season, he could afford to take that gamble.

We always hear a lot about top speeds and how the power units and the differing horsepower levels contribute to that.

This is a comparison of chassis and power unit performance taken using each engine's highest and lowest speed trap figure during Q2. The aim of this is to show that there is a difference from chassis to chassis with the same engine.

Mercedes
Esteban Ocon fastest with Force India chassis, 220mph
Valtteri Bottas 10th with Mercedes chassis, 215mph

Ferrari
Kevin Magnussen fourth with Haas chassis, 217mph
Kimi Raikkonen 12th with Ferrari chassis, 215mph

Renault
Daniel Ricciardo 13th with Red Bull chassis, 215mph
Carlos Sainz Jr 18th with Renault chassis, 212mph

Honda
Fernando Alonso 16th with McLaren chassis, 214mph
Stoffel Vandoorne 19th with McLaren chassis 208mph

Chassis drag plays a big part in the top speed of any car. Deciding on the compromise between downforce and hence drag, which gives you grip and cornering speed against top speed, is like walking a tightrope without a safety net.

I remember at Spa Michael Schumacher once asking his Ferrari team to reduce the rear wing levels as he wasn't fast enough on the straight. The reply was: 'But you will be slower in sector 2'. His answer was simple: 'Let me look after sector 2'.

As a driver, that's exactly what you have to buy into when you are searching for the best drag/downforce compromise for a given package and circuit.

Force India has always built a very efficient chassis and being fastest overall on that long straight shows it's still following that route.

Constructors' champion Mercedes, using the same or perhaps a little bit better power unit specification, is 5mph slower than Force India at that point but faster in lap time.

So the big question is, would Force India have done a faster lap time with a little more downforce but slower top speed?

And on the opposite side, would Mercedes have done a faster lap time with less downforce giving it a higher top speed but a small reduction in cornering speed?

The teams do thousands of lap simulations using many set-up permutations, so they should come to the track with the best compromise as far as the downforce and drag levels are concerned.

But this all depends on how well the simulation correlates with the track. In some cases, I am not so sure that the correlation is as accurate as it needs to be.

As for McLaren, we often hear Alonso saying that the car is great and in Mexico after Q1, when he was fifth fastest, he made the bold statement that McLaren had the best chassis on that day. Up against Red Bull with the same Renault engines next year, that can be tested.

Mexico City is a challenging circuit. It's 2285 metres above sea level, so the air is a bit thinner than normal, meaning cars with the same aerodynamic set-up will produce roughly 75% of the downforce and drag they would at sea level. This is why top speeds are so high.

The engine power is not quite as high as normal because of the lower air density, but by working the turbo harder you can make up for most of the losses.

So the engine itself should be that little bit more reliable, but as we saw there were four Renault retirements and at least three of those looked to be connected to the turbo.

Temperature management is also very difficult, and bigger and better cooling ducts were the order of the day for everyone. Or if not, they should have been.

Whatever the altitude, Hamilton has unquestionably done a superb job this season. In a tricky car to get to work, against a strong Ferrari, he's the one who has got the job done.