Hamilton: We've not been on low fuel yet during testing

Vettel shattered the lap record during a run on Thursday where he circulated around the Spanish Grand Prix venue in a time of 1:17.182 which was a full second faster than his closest rival on the day.

Hamilton ended his half-day, in the cockpit of the W09, over two seconds down on the top time but it must be pointed out that Mercedes were focussed on race simulations and acquiring long-run data gathering on the day.

When told about Vettel's benchmark time, Hamilton was not perturbed, "Oh, I don't know if that's a good time or not. I don't think it's faster than what we did a couple of days ago. I don't know if it's a qualifying run, I don't really know, I don't really care."

"It's testing. I think someone said I was down in 11th today – it doesn't matter. It matters where we are in qualifying, in Q3 in the first race when everyone's on low fuel."

"For example, we've not been on low fuel yet, so I have no idea where the car can go. I hope it's good – I hope it's a good, good time so that means that they're strong and that means we have a race on our hands."

Mercedes have dominated the last four years with Ferrari and Red Bull occasionally getting a look in, but Hamilton himself is relishing the prospect of a more intense battle with rival teams, "Of course, the ultimate goal is that we hopefully have more teams fighting for the championship."

"I think there was one year where had six different winners in the first six races, or whatever it was. That's only good for the sport. The more competition there is, the more fun it is to watch."

"I, like you, have grown up watching the sport, being a fan of it and seeing it when it's been a one-team championship and seeing it when there's been a couple fighting, so I am really hopeful."

"Red Bull could be a real challenge this year – their car looks great and I haven't seen anything from what Ferrari have been doing, but for sure they'll be good. It's going to be exciting."

Hamilton will spend half of the final day of testing in Barcelona sharing the Mercedes W09 with Valtteri Bottas and predicted, "I think [Friday] we will hopefully be doing a race distance, as Valtteri did [Thursday], which I believe went well."

"In that, it's more like competition, so that's where you take it a lot more seriously and really try to take a lot more notes, because the cars are behaving differently between each run, the settings... you might need to change all those little things," explained the reigning F1 world champion.