Hamilton: The most impressive first day I've had

Triple Formula 1 world champion Lewis Hamilton completed the equivalent of nearly 2-1/2 race distances on what he said ranked as his best ever start to pre-season testing on Monday.

The Mercedes driver completed a massive 156 laps at the Circuit de Catalunya -- where the Spanish Grand Prix lasts for 66 -- to eclipse the mileage of all his rivals as the new cars hit the track for the first time.

Ferrari's Sebastian Vettel, who was fastest overall and 0.470 of a second quicker than the 31-year-old Briton, did 69 laps in total.

"Today is just a real show of just how amazing this team is," said Hamilton. "From as far as I can remember, and I've been driving a long time, I'm certain this is the most impressive first day I've had," he added.

"If you look back at the first days I've had in 2013 and maybe 2014, I had those glitches with the brakes so it's nice to have a clean day without any issues with the car. Really just go above and beyond."

Hamilton, champion in 2014 and 2015 with Mercedes, had completed a race distance by lunchtime and told reporters anxious for first impressions that the car felt just like last year's dominant one.

"It's good to be back. It really had felt like a while - but now it feels like home already. I'm glad to see I can still drive! The car has been great so far. It's very similar to last year's - which is a good thing, as it gives us a great foundation to work from."

"The key is to get as much mileage as possible in the short time we now have for testing and we've made a fantastic start. The team has done an incredible job to get the car running the way it has - completing so many laps with no real problems."

"That's seriously impressive on the first day, so fingers crossed it continues. The tyres feel a little different and we'll work to understand them better in the coming days. Barcelona is one of the best circuits to test a new car, too."

"It's got a wide range of corners and the weather's always good, so overall it's been the perfect way to kick off the year. Of course, it's still early days. It's hard to say how the others look at this point and we won't know how competitive we are until everyone really starts pushing. But we're not looking too bad, that's for sure."

Despite the strong showing, Hamilton - who has won the past two championships and is aiming to become the first Briton to win four world titles - said the season starting in Australia on March 20 would be tough.

"Every year you have to expect it to be harder. In terms of my preparation, I’m preparing for the hardest season I’ve had so far," he said.

"I hope the Ferraris are up there with me and Nico this year, as that would be exciting for the fans and exciting for me too," added Hamilton.