Sebastian Vettel has admitted he is a "bit surprised" to see
Mercedes bring the amount of upgrades they have to the Formula 1 pre-season test in Barcelona.
Mercedes, last week, admitted they were behind
Ferrari but in their W10, they rolled out some major aerodynamic upgrades on Tuesday.
Asked if he kept a close-eye on Mercedes' upgrade, Vettel replied to Motorsport.com: "Yes. You definitely look at it. That interests me too.
"I was a bit surprised that the car had so many innovations, but everyone chooses their own way. Of course, it's interesting what's happening here (in Barcelona), but it's only in Melbourne that we really get going."
The German four-time world champion admitted that the way testing is, he doesn't focus too much on the leaderboard.
"I haven't analysed the times exactly yet," he continued. "We have a few people with us who are better at that than I am. Red Bull definitely looks very strong and consistent, and reliable so far.
"There are a few surpises. Alfa (Romeo) looks very good. At Mercedes it's hard to say exactly what's happening from our point-of-view at the moment. Some runs look very good, others less so. But that is all part of testing."