Kimi Raikkonen was surprised not to feel a bigger difference between Ferrari and Sauber's 2018 Formula 1 cars after completing his first test with the latter in Abu Dhabi last month.

Raikkonen will race for Sauber in 2019 after spending five years with Ferrari, and was given permission to link up with the Swiss team early for the post-season running at the Yas Marina Circuit following the Abu Dhabi Grand Prix.

Raikkonen completed one day behind the wheel of Sauber's C37 car in order to get to know the Sauber team better, but the Finn admitted he was surprised not to feel a bigger difference compared to Ferrari's SF71H car from the 2018 season.

"I think it felt very similar to what I’m used to," Raikkonen said.

"It’s a different car, looking a bit different, but to be honest it wasn’t a lot different feeling.

"I probably expected a bigger difference.

"[I was] just testing the tyres and not really dong any setup work, just in the car doing laps and trying to see what is what. I think as a first experience, it was OK."

Raikkonen will return to Sauber after 18 years away, having made his debut with the team back in 2001. He spent one year with Sauber before being snapped up by McLaren for the 2002 season.

While it will mark a step down the grid after five years in his most recent stint with Ferrari, Raikkonen is excited by the challenge offered at Sauber, and is confident the team can produce a good car for next season.

"I am excited. It’s different obviously, obviously I’ve been in teams with a lot of different people now," Raikkonen said.

"I think they have all the tools, they have a great wind tunnel, they have everything to build a great car. Obviously we have a Ferrari engine, so we know what we’re going to get.

"I don’t see a reason why we can’t do a good job out of it. Where that’s going to take us, we’ll see next year.

"But for me it was important to just try the car and see if there were any big things that we need to fix, but it was pretty straightforward."