* Hamilton quickest in both practice sessions
* Briton celebrates fourth title with helmet stars
* Champions Mercedes dominant at Interlagos
* Red Bull taking a ‘conservative’ approach (Adds Hamilton quotes)
SAO PAULO, Nov 10 (Reuters) - Lewis Hamilton, with four world championship stars freshly painted on his race helmet, smashed the Interlagos track record as Mercedes dominated Brazilian Grand Prix practice on Friday.
Showing no let up after clinching his fourth world title in Mexico two weeks ago, Hamilton was quickest in both sessions with a best time of one minute 09.202 seconds in the sunny morning session.
Finnish team mate Valtteri Bottas was second in both and ended up just 0.048 slower.
“It’s been a good day,” said Hamilton, who arrived at Interlagos on Thursday nursing a cold and will be chasing his 10th win of the season on Sunday. “It was pretty exciting to come to the track with the cars being so much faster this year.
“Unfortunately the tyres don’t last very long so you only get one or two laps on the short runs. Overall, we got through what we needed to do. We’re in a decent position but I think it could be quite close.”
The previous track record of 1:09.822 was set by Brazilian Rubens Barrichello in 2004 qualifying for Ferrari.
Hamilton, who accused Renault’s Nico Hulkenberg over the radio of dangerous driving in forcing him wide onto the runoff in the morning, was half a second faster than Ferrari’s Kimi Raikkonen before lunch.
The Finn had been closest to the Mercedes duo in the first session but Australian Daniel Ricciardo filled that position later on for Red Bull.
His 20-year-old Dutch team mate Max Verstappen, winner of two of the last four races, was fourth and fifth on the respective timesheets.
Team principal Christian Horner said Red Bull had played it safe due to reliability concerns and the need to make the engine last.
Ricciardo will have a 10-place grid penalty for Sunday’s race, after a change of his Renault power unit, while both drivers for the Red Bull-owned Toro Rosso team suffered costly failures.
“I think they (Renault) are really struggling to understand what are the root cause of these issues,” said Horner.
“So we’re running super-safe and conservative in these sessions, which explains quite a bit of the deficit to the Mercedes at the moment.”
Ferrari’s Sebastian Vettel, who had an early spin, was sixth and fourth respectively.
“Mercedes looked very strong so I think they are a bit ahead, both of them,” said Vettel, who has won four times this year. “Then I think it is very close between us and Red Bull.”
Mercedes have clinched the constructors’ championship for a fourth successive year and experimented with processes and parts for 2018.
With none of the top four teams able to improve their placings or in any danger of dropping down the order, others were also turning their thoughts to next year.
“Obviously, both cars have got bits that they (the engineers) are having a look at for future events,” said Horner.
New Zealander Brendon Hartley, who won the world endurance championship for the second time last weekend, failed to set a time on the morning of his 28th birthday thanks to an engine blowup while French rookie Pierre Gasly also stopped early on.
“I don’t know the track so for me it was really important to get some running,” said Gasly before both went out in the afternoon.
British driver George Russell, the 19-year-old GP3 champion, made his grand prix weekend debut with Force India and was an impressive 12th fastest at an unfamiliar circuit and in a car he had not driven before. (Reporting by Alan Baldwin in London, editing by Ed Osmond and Christian Radnedge)