Mercedes has won the last three grands prix, but its pace-setting speed in Singapore and Russia has left title rival Ferrari on the back foot.
Hamilton says that the way Mercedes has overhauled Ferrari in pace terms has been a surprise, but he does not think the explanation comes from any new parts of the car.
“We were not expecting to be as fast as we were in the last race,” explained the world championship leader. “I think our car worked really well but it is difficult to know how much we have improved or they have stood still, or they have gone backwards. We have no idea.
“Maybe we will have a better understanding when we come here. It is expected to be quite close here.”
What Hamilton is convinced about, however, is that much of the progress made at Mercedes has come from the team having properly unlocked all the potential in its car.
“We had an upgrade in Spa and then we had a small upgrade in Monza and then we had a small upgrade in the last race, so it is not big steps, it is small bits,” he said.
“But our understanding of the car is continuing and our understanding of the car is where we are making the biggest steps. All around the car feels great.
“Engine performance is improving, efficiency is improving, and car stability is improving. It is a good point of the year because the car is the best it has been all year long
“So I cannot wait to drive around this track as it will be the fastest we’ve driven around here in Suzuka. That first sector is going to be insane.”
Hamilton says the run of form that has helped him to five wins from the last six races has been the stuff of dreams.
“I could not have hoped for better performances,” he said. “When I look back, there have been some real dream experiences for me – races I dreamed of having and performing at those levels.
“That is what I live for. You don’t always get to experience what your target is. I am just grateful for the races I have had and how a lot of then have panned out.”