Three things we learned about the Chinese Grand Prix from Friday practice

The Shanghai International Circuit has been as happy a hunting ground as Mercedes have enjoyed in the hybrid era but Lewis Hamilton and Valtteri Bottas will have pressure on them like rarely before at this weekend's Chinese Grand Prix and perhaps their advantage has been wiped out...

LEVEL PEGGING UP TOP

Hamilton was two tenths quicker than Sebastian Vettel in qualifying last year, and five tenths quicker than Kimi Raikkonen, before going on to seal the race win, but the gaps appear to have shrunk.

Hamilton, Raikkonen, Bottas and Vettel's quickest FP2 laps were separated by just 0.108 seconds and the huge, almost 1.2-kilometre back straight didn't appear to play into the Silver Arrows' hands as previously.

Raikkonen went slightly quicker than Hamilton in the third sector, but was behind the world champion on overall lap time - albeit by seven thousandths of a second.

Red Bull again look in close attention, Max Verstappen was within three tenths of the quickest time.

In pre-season, Verstappen claimed Red Bull would be able to win races if they could qualify within that timeframe of their rivals, so the signs look positive.

There was little to split the teams on long-run pace, although Ferrari's running was limited and a rain shower late in the session cut everyone's time.

FP2 INITIAL CLASSIFICATION (90/90 MINS): Nip and tuck between Mercedes and Ferrari #ChineseGP ???????? #F1 pic.twitter.com/PsqrotVSfk — Formula 1 (@F1) April 13, 2018

RICCIARDO RELIABILITY WORRIES?

The only leading car not in that tight-knit pack was the Red Bull of Daniel Ricciardo, who ended FP2 seven tenths down on team-mate Verstappen after suffering discomfort with braking.

After a grid penalty hampered him in Australia and his car completely shut down in Bahrain, Ricciardo won't want to see another race ruined by factors outside of his control.

Perhaps comforting for the Australian will have been his long-run performance, which suggested he should be right in amongst the leading times - providing he can start close enough to them!

ANOTHER BOTCHED PIT-STOP

It's an issue that will not go away. Stoffel Vandoorne was the latest driver to be released from his pit-stop with a wheel not properly attached.

Footage of the stop showed that McLaren's right-rear wheel-gun flashed green to signify the wheel had been attached, but a fine will now be heading their way.

The FIA have confirmed an investigation will be taking place after the horrific pit-stop at Ferrari last week which left mechanic Francesco Cigarini with a broken leg.

Similarly to the Raikkonen pit last week, the systems, rather than humans, seem to be at fault.

????@svandoorne

"I need to stop the car. The tyre is not on" #ChineseGP ???????? #F1 pic.twitter.com/fPkiKTOFXY — Formula 1 (@F1) April 13, 2018