Engine worries leave Mercedes vulnerable

Ferrari and Red Bull should head into the rest of the Japanese Grand Prix weekend with quiet confidence. Despite the fact Mercedes yet again finished Friday practice one-two on the timesheet, its two main Formula 1 rivals of recent times look very much still in the hunt.

In theory Mercedes should utterly dominate at Suzuka, like it has done the past two F1 seasons. It was fastest easily over one lap in Malaysia, and even more time is spent at full throttle at Suzuka than Sepang, which theoretically favours Mercedes' engine advantage even more.

But Mercedes has to be cautious with the way it runs its power units here, particularly with regard to the oil. Lewis Hamilton's spectacular engine blow-up while leading comfortably in Malaysia last weekend, now traced to the failure of a big-end bearing in the crankshaft following a loss of oil pressure, understandably makes the manufacturer nervous.

So it has set conservative parameters for running all its engines this weekend, while it investigates exactly why that bearing let go in Hamilton's unit so suddenly.

This is bound to cap the ultimate performance of F1's most dominant car, and it was interesting to see Ferrari's Kimi Raikkonen lap within 0.323 seconds of Nico Rosberg in the second free practice session, despite fighting significant understeer through the Esses at the start of the lap.

PURE PACE RANKING

1. Mercedes (Rosberg) 1m32.250s
2. Ferrari (Raikkonen) 1m32.573s
3. Red Bull (Verstappen) 1m33.061s
4. Force India (Perez) 1m33.570s
5. McLaren (Alonso) 1m33.985s
6. Williams (Bottas) 1m34.028s
7. Toro Rosso (Sainz) 1m34.086s
8. Haas (Grosjean) 1m34.241s
9. Renault (Magnussen) 1m34.339s
10. Sauber (Nasr) 1m34.824s
11. Manor (Wehrlein) 1m35.292s

"The feeling is far from where we want it to be," said Raikkonen, who was surprised to be as quick as he was. "It got a bit better in the end, but it feels like you're fighting with the car in the first sector - just too much understeer and not getting the power we want.

"Obviously there's a lot of lap time in the first sector. If we get the feeling and the car working as we want there's a lot of lap time [to be had]."

Even with this handling imbalance, Raikkonen gave away just over a tenth in each of the first two sectors of the lap. Through the final chicane and the last corner he trailed Hamilton by just 0.003s.

Provided Ferrari has avoided running much lighter than Mercedes in practice, this bodes well. Mercedes will surely turn its engines up for qualifying, but with those reliability concerns the improvement will probably not be as dramatic as usual.

Autosport understands Mercedes' conservative settings are costing significant lap time. Not three tenths, but not milliseconds either.

"I had decent one-lap balance, the times are OK and on race pace we're looking good as well," said Rosberg.

"Balance has to be spot-on here. It's so crucial in those Esses, because one corner leads to the next, and if you get the first one a bit wrong then the rest of them are going to be wrong too, so you really need to nail it."

That's certainly where Mercedes seems to have got things right so far. The car picked up understeer in the first session, but by the afternoon's running both drivers were happy with their set-ups.

Red Bull is also in pretty decent shape over a single lap, despite ultimately trailing Mercedes by more than eight tenths of a second in the afternoon.

Max Verstappen and Daniel Ricciardo were both hampered by a turbo failure on Esteban Gutierrez's Haas, which forced the Mexican to park his car to the side of the circuit, and necessitated a virtual safety car period while marshals used a crane to remove it.

Ricciardo was forced to abort his qualifying simulation, so ended up way down the timesheet on account of setting his fastest time on the hard compound, while Verstappen dived for the pitlane at the end of his out-lap.

He returned to the track once the Haas was removed, but lost too much tyre temperature during his stay in the pits to post a representative time. By the time his rubber got up to snuff the lap was in its final stages.

The best we can do to approximate Red Bull's true single-lap pace is combine the best of both cars. Verstappen did the better first sector, despite that lack of tyre temperature, suggesting he can go faster still than three tenths shy of Mercedes through the Esses and the Degner Curves.

Ricciardo produced a decent middle sector, within a tenth of the pace, before having to abort, while the final part of Verstappen's lap was only 0.060s off the reigning world champion's time.

A Red Bull 'superlap' puts the RB12 at 1m32.762s, about half a second away from Mercedes, but it's fair to say Verstappen and Ricciardo could do better than that with a clean run, particularly in the first sector.

There is not much more to come from the engine, and in fact Red Bull has reverted to Renault's pre-Singapore ignition specification, while retaining the latest Total fuel, but there is still confidence within the team that it can carry the fight to Ferrari.

"The lap I had to abort would definitely have been in the 32s, so probably would have put me just behind Kimi's time," reckoned Ricciardo, who thinks wet weather forecast for Saturday would put Red Bull in an even stronger position for qualifying.

"Ferrari look pretty strong, but we're close enough, and on the long run on the hard tyre we seemed pretty solid.

"I expect the rest of the season to be tight. Here, if we get the car hooked up in qualifying then we can be close to Mercedes, and hopefully ahead of Ferrari."

Analysis of the longer runs suggests things could be pretty close in race trim. Raikkonen was almost two tenths faster per lap on average than Hamilton's Mercedes, and over five tenths quicker than the Red Bulls, suggesting Ferrari has the edge on the soft tyre.

But Raikkonen completed his run much later in the session than the others. He also went out fast and began to lose the tyres after just three laps. Rosberg's Mercedes and the Red Bulls both had a big drop-off after four, while Hamilton got more impressive life out of his, but only by starting off at much more conservative pace.

There was little to choose between Hamilton and the Red Bull pair on the hard tyre, which Pirelli has mandated must be used if Sunday's race is run in dry conditions.

It looks from the graph as though traffic played a role in these runs, but Verstappen's pace was particularly strong relative to the Mercedes before a sharp drop-off after half a dozen laps.

Sebastian Vettel did a much longer run on the hard compound, but it was not competitive and he complained about the balance of his car afterwards.

Rosberg outpaced Raikkonen on the medium, by about four tenths of a second per lap on average, but they did these runs at different points in the session - Raikkonen much earlier than Rosberg.

But this may all be rendered moot if the rest of the weekend is rain-affected.

"Usually here Red Bull are very strong, particularly on intermediates they are very, very strong," said Hamilton.

"But we were quick here on the extreme [wets] last year. The track is much more fun to drive in the dry, but if it rains that's OK.

"It's very, very easy to make mistakes [in the wet], but you drive by the seat of your pants and it's just about being sharp and being responsive and hopefully making the right decisions when you need to.

"I'm very happy with the car. There's time for me to find in myself, that's what I'm going to try to unlock.

"Usually I'm quicker in the first sector, so I've got to find at least a tenth there. The middle sector I would say a tenth and a half to two tenths, and then in the last sector probably another tenth. That's where I feel I should be."

But Hamilton will have to dig a bit deeper than usual on account of those conservative engine settings. Ferrari could potentially threaten if it balances its car better, while Red Bull is definitely faster here than it looks on paper.

Mercedes is of course still the favourite, as ever, but Ferrari and Red Bull are close enough to apply some serious pressure if F1's top dog slips up.