Real Madrid ace Cristiano Ronaldo says competition with Barcelona's Lionel Messi is making him a better player.

He believes it is futile to debate which player is better, but is inspired by his opposite number's high standards.

"Sometimes it makes me tired...for him too because they compare us together all the time," he told CNN World Sport.

"You cannot compare a Ferrari with a Porsche because it's a different engine. You cannot compare them.

"He does the best things for Barcelona, I do the best things for Madrid, so the number (of goals)...everyone says 'it's incredible'. For him and for me because we beat our own records, so it's amazing.

"I think we push each other sometimes in the competition, this is why the competition is so high. This is why Madrid and Barcelona are the best teams in the world because everyone pushes each other."