Cape Town - Lewis Hamilton believes Red Bull are the "big unknown" in the build-up to this year's championship as the Milton Keynes' team are "amazing at creating downforce."
Formula 1 is welcoming a new era this season with wider tyres, wings and bodywork, all of which have increased the downforce of the cars.
And that, Hamilton says, could play into Red Bull's hands.
He said in an interview with BBC Radio 5 live: "It's a completely new slate. It might be Ferrari at the front, it might be Red Bull, we have no idea.
"I think the big unknown is Red Bull, I think they always create an amazing car and this is a new area of downforce and they're amazing at creating downforce so I think it'll be really interesting to see what they pull out and I'm hoping it'll be a real mixture of competition.
"I hope it'll be close so we'll be fighting with Red Bull and Ferrari. That's what the fans want to see."
The Mercedes driver also touched on overtaking, which many fear could be hampered by this year's new regulations.
"My engineers say it's going to be a lot harder to overtake," he said.
"If we see overtaking is worse, it's going to be worse for the fans, the spectacle will be worse so I'm hoping that's not the case.
"For example, I heard tyres might not be as grippy as we'd hoped but the aero downforce is going to be huge because it's a bigger, wider car so there's going to be more downforce, so the car behind will be affected even more than it ever was before.
"And I've heard the engineers said this would potentially happen and there is an alternative route but this is the route that's chosen.
"So we are where we are and I really hope that the engineers, who are the smartest guys, are wrong and I hope that the spectacle is greater and the most competitive that it's ever been and if it is, then I look forward to being part of that."