Red Bull boss Christian Horner has admitted that he is happier with his team's pre-season progress compared with the same time last year.

The Milton Keynes-based outfit registered the second fewest laps of the constructors at the first test in Jerez, but Horner has insisted that there are no fundamental problems with the car.

He told Red Bull's official website: "It was a lot more positive than last year. We had issues but they were not major ones compared to the fundamental problems we had last year, with the car not running cleanly or overheating or simply setting itself on fire!

"Yes, we had a few niggling issues but this was much more of a standard pre-season test than the one we experienced 12 months ago."

Red Bull picked up three race wins in 2014 thanks to Australian driver Daniel Ricciardo.