Feb.12 (GMM) Forget the 'big three' -- Christian Horner has admitted teams other than Red Bull, McLaren and Ferrari made the "strongest impression" on him last week at Jerez.

Christian Horner, Red Bull Racing Team Principal
Christian Horner, Red Bull Racing Team Principal

Photo by: XPB Images

"Lotus and Sauber left the strongest impression," the Red Bull chief said, according to Germany's Auto Motor und Sport.

"All the others are still difficult to assess," added Horner.

The German magazine's correspondent Michael Schmidt said the new grey Sauber had Nico Hulkenberg "smiling" all week as the opening test at Jerez unfolded.

"Eyewitnesses say the C32 is the best car in the field in fast corners," said Schmidt.

Swiss newspaper Blick's veteran correspondent Roger Benoit, meanwhile, quoted Hulkenberg as confiding to his Sauber colleagues: "Guys, this car goes like the devil."

As for Lotus, both Romain Grosjean and Kimi Raikkonen each tasted the top of the timesheets during the four-day test.

"We are quite surprised," admitted the always-grinning Frenchman Grosjean, according to RMC. "I think everybody saw my smile."