ABU DHABI -- Having declined the opportunity to do so in previous seasons, Lewis Hamilton has been granted permission to run the number one on his Mercedes for this weekend's Abu Dhabi Grand Prix.
A rule in 2014 gave drivers numbers they kept for their entire career. Hamilton picked 44 and won the championship that season.
The number one has traditionally been carried by the driver who won the title the previous season but the new regulation made it optional -- Hamilton continued with his career number when defending champion in 2015, 2016 and for the current campaign.
However, for this weekend Hamilton made a special request to carry the No.1 on the front of his Mercedes, having already wrapped up the championship. His 'entry' number remains 44 and that will remain on the official timing screens for the weekend, as well as on the engine cover towards the back of the car. He ran it in Friday's opening practice session.
Hamilton fondness for the number he chose as it was what he raced with in go-karts.
Speaking about his reluctance to take the number for 2018 after winning last year's title, he said: "You know, you could fit the No.1 within the 44, so maybe you can play around with it. But I don't really like the number itself. People had it in the past, Michael [Schumacher] had it, but no one's had 44 except me.
"It's been a good number for me since I started. I think it's the number my fans recognise and can relate to more. The No.1 is good for a moment but you can't live with it forever. Whereas 44 will stay with me forever."
It marks the first time the No.1 has been present on a Formula One car since the 2014 Abu Dhabi Grand Prix, when Hamilton won his second championship. That was the final time Sebastian Vettel competed as defending champion before reverting to the number he chose, five.
The only other person to win the championship since the new regulation was Nico Rosberg, but he retired after doing so in 2016, meaning he never had the chance to carry the number on the front of his car.
It is not the only one-off change being made to a car this weekend. Fernando Alonso is driving a McLaren carrying a special paint job to celebrate his final grand prix -- the rear of the car carries the blue, red and yellow colours he has worn on his race helmet for the majority of his career. The colours are of his home region Asturias and nation Spain.
Hamilton had reverted back to running the No.44 on both ends of the car in time for Friday's second practice session.
No engine change for Hamilton
Hamilton won last time out, in Brazil, despite Mercedes' fears of a mid-race engine failure. The team has confirmed the issue was rooted in a failure of the variable inlet system which caused an unstable combustion. Engine settings were changed to contain the risk while also maximising performance.
This weekend, Mercedes is running the same engine for both Friday practice sessions. The unit will then be reviewed after FP2 to make sure it is fine to continue for qualifying and the grand prix.
A change to a new engine at this point of the season would result in a grid penalty for Hamilton, presuming he does not have an old unit to switch back to.