Hamilton surprised McLaren-Honda lasted so long

The anticipated divorce was finally made official on Friday in Singapore, the Woking-based squad switching to Renault power units from next season onwards.

Hamilton said he hopes that McLaren's split with Honda will allow the team to compete with Mercedes at the front of the field.

"I'm surprised it didn't happen sooner, to be honest," said Hamilton. "It's been a long, hard slog for the both of them.

"Hopefully this will spark a new start for McLaren, because they should be in the fight with us," added the Briton, who drove for McLaren from 2007 to 2012.

Tough battle in Singapore

Hamilton was third-fastest behind the Red Bulls in Singapore on Friday, some 0.7s off pacesetter Daniel Ricciardo, and he reckons Mercedes is facing a tough task in trying to beat its rival.

"We've been thrown a seriously tough battle this weekend at this circuit, which is such a hard circuit to dominate, it's very track-specific here with the car," Hamilton said after Friday practice.

"Whether or not we'll be dominating here, we shall see. I think the Red Bulls look like they are dominating at the moment.

"Clearly Red Bull were out there on their own today, they just seemed to have an extra bit of juice. I don't know where they got it from. I think tomorrow it might close up a bit, but I still think they are going to be ahead.

"I don't know what we can do to close the gap with them, they are just rapid in the last sector, but that's how they always are. They always seem to be able to keep temperature up in their tyres, for whatever reason. We knew it was going to be a difficult weekend."

Hamilton believes that some set-up limitations may make it hard for Mercedes to improve the W08.

"The car feels OK in general, but we need a little more grip. It's a bumpy circuit, so the car could be better in some areas.

"There are some limitations with the car, so I could go faster if there were some things that we could fix. Whether or not we can do it with set-up – it might just be a fundamental thing.

"There are some big things, as I said I don't know whether or not we can fix the big things, but the small things we can definitely improve."