The supposed Ferrari edge that makes China so vital

Mercedes narrowly set the pace on Friday in China, 24 hours after its drivers expressed quite severe concerns. Lewis Hamilton said Mercedes faces a "very, very hard" prospect of trying to cut into its Formula 1 rival Ferrari's major engine advantage, if the edge it had on the straights in Bahrain is real.

Valtteri Bottas added that making up a four tenths of a second deficit, which is roughly what Mercedes (more than once) thought it was losing on the straights at the previous race, is "very difficult" over one season.

As we have already explored, Mercedes' pace in China sets the scene for F1's top two teams' first real head to head fight of 2019. But the events of this weekend could be critical to much more than just the quality of this season's show.

After Ferrari's unexpected slump in Australia gave way to an unexpected (according to Sebastian Vettel) top-speed advantage in Bahrain, China presents an opportunity to see where reality lies on that spectrum.

The jury's still out on what Ferrari advantage actually exists in a straight line, and whether or not it translates into a faster overall lap time. This is because Bahrain performance was impacted significantly by downforce levels: just look at how much the Haas was a sitting duck in race trim in a "hopeless" Sunday performance because it did not have an appropriate, lower-drag, set-up.

"In Bahrain, [Ferrari] were superior to all of the other teams," said Mercedes team boss Toto Wolff on Friday in China. "There was a massive engine power [straightline speed] on the straight but it's not always [because of] engine power.

"The drag levels are playing an important role in the calculation. This is something we need to evaluate."

Bottas agreed that it was too soon to declare Bahrain the pattern for the season, but also acknowledged the significance of getting more data from China.

"It seems like a big difference on the straights," he said. "That is how it was in Bahrain but it's only one track and there are different downforce levels you are running that also affect quite a lot. We are going to see here again, but four tenths in terms of the power of the engine is very difficult to gain over one season."

"It's very, very hard to make big gains without taking risks, especially with the regulations that we have these days" Lewis Hamilton

The Ferrari top-speed factor is clearly an edge that has Mercedes' drivers anxious. Rightly so, because as Wolff pointed out: "If somebody does a good job he does a good job. That's fact. Whether he has a good engine that outperforms all the others or a decent amount of downforce and goes quicker around the corner, that is irrelevant."

If Ferrari establishes this weekend that it has a pace advantage then it would suggest its engine gains are playing a decisive role. This is where the fun starts for everybody watching, and the hard(er) work begins for Mercedes.

Wolff says there are two races this season: who came out of the blocks quickest, which Ferrari seems to have done in terms of performance despite Mercedes leading the way in results, and who develops best over the year.

If the fears of Hamilton and Bottas are accurate and Ferrari's straightline speed advantage has given it a vital edge, the onus is very much on Mercedes to win the second of those races. That will be tricky on the engine side.

"It's very, very hard to make big gains without taking risks, especially with the regulations that we have these days, with the small amount of engines and turbos [available in a season]," said Hamilton on Thursday.

"Those steps are harder to come by. I think it's probably a combination of a couple of things. But closing that gap on straightline speed, it's not something that you'll see close up particularly quickly."

Mercedes' excellent teams at Brackley and Brixworth will already be working through their pre-defined programmes and seeking performance gains, of course. But it has not dominated the V6 turbo-hybrid era because it likes to stand still, and top-quality opposition will always move the goalposts and bring out a little bit more quality.

Wolff said after first practice at Shanghai on Friday that the straightline speed on Vettel's lap was "frightening".

"But it is what it is," he added. "We have to stretch ourselves and fight and extract performance out of the chassis and out of the power unit. Having a benchmark like that helps and motivates."

As Hamilton and Bottas stressed, making up an engine disadvantage is not the work of a moment. That means reacting swiftly to setbacks and identifying new priorities when the competitive picture becomes clearer is vital. Qualifying and the race this weekend will be important in establishing what Mercedes, or indeed Ferrari, does next.

Last season, Mercedes fell behind properly for the first time in this era - and excelled in its response. Crucially, two major engine upgrades, introduced in France (after a one-race delay) and Belgium, represented its biggest performance steps.

The quality Mercedes displayed in sweeping to five consecutive title doubles over the past five seasons stands as evidence of its prowess with the complex V6 turbo hybrids. Its fightback last season is proof it has the qualities to respond to someone else raising the bar too.

In the meantime, Mercedes has proven it can win even if its car is not the fastest. Maintaining edges in other areas will be vital if Ferrari's straightline speed advantage wins out here.

"My confidence and our focus and attention have not wavered," said Hamilton. "I'm still very, very confident within my guys that we can extract more on weekends.

"It's not just about straightline speed. It's about cornering performance, it's about reliability, it's about the mechanical side of things. It's about pitstops, these kind of things, the driver, due diligence. It's making sure you have all those things ticked off."

If that does not happen, and Ferrari's supposed new edge does prove real, there is still no better candidate to hit back than Mercedes. Ferrari might have more "frightening" laps in store this weekend, but Mercedes has what it takes to face them down. It is unlikely to run scared.