Fernando Alonso has hailed Mercedes as the new benchmark for Ferrari, saying they have been a "good surprise" to F1 this season.
After four consecutive World Championships many believed Red Bull would once again carry that form over to this campaign, but that hasn't been the case as Mercedes have adapted better to the new engine rules.
Nico Rosberg and team-mate Lewis Hamilton have dominated the Drivers' Championship, winning nine races between them to occupy the top two places in the standings and Paddy Power has them neck-and-neck to win the World title.
Alonso admits he has been impressed by the way Mercedes turned things around after the pre-season tests.
"Mercedes have surprised everybody," he told Press Association Sport.
"Now we are getting used to seeing them dominate every weekend, but I remember when we were in Jerez and Bahrain testing these new cars with very complex technology.
"We were all struggling, but straight away they were okay, and now from 11 races they've won nine and nearly always been on the front row.
"I would say they have been the biggest surprise - a good surprise - this year."
While Mercedes have been excellent, Ferrari have stuttered again this season with Alonso picking up just two podiums to lie fourth in the standings and 87 points behind Rosberg. His team-mate Kimi Raikkonen has fared even worse as he has scored just 27 points.
The two-time World Champion believes the Italian outfit can learn a lot from their Brackley counterparts.
"Mercedes are motivation for us," added the Spaniard, who is an outsider with Paddy Power to win in Belgium, but if anyone can do it then it's Alonso.
"We know we can do a much better job as we haven't done a good one so far.
"We are making some progress, but the benchmark has changed - last year it was Red Bull, this year it's Mercedes.
"We simply have to get on top of our problems and try to arrive at their level."