Vettel leaving Ferrari

MEXICO CITY (Reuters) – Sebastian Vettel's expletive-laden radio rants betray his frustration at Ferrari's fading form, according to his former Red Bull team mate Daniel Ricciardo and predecessor Fernando Alonso.

Four-times world champion Vettel turned the air blue in Sunday's Mexican Grand Prix, directing some of the abuse at Formula One race director Charlie Whiting in an outburst that some in the paddock compared to slapping a soccer referee.

It was not the first time this season that the German has let rip over the airwaves with bleeped-out swear words broadcast worldwide.

He called McLaren's Alonso, a double world champion who left Ferrari in 2014 when Vettel arrived from Red Bull, an 'idiot' in free practice at the Autodromo Hermanos Rodriguez.

The Spaniard laughed off the insult by saying Vettel was "living a very frustrating period for himself and for Ferrari, so we have to forgive him".

Much of his ire has been aimed at Max Verstappen, Ricciardo's team mate, and he had plenty to shout about on Sunday after the Dutch teenager cut a corner while defending against Vettel and refused to give up the place.

Verstappen, who has annoyed plenty of other drivers, suggested Vettel go back to school to improve his language.

Ricciardo, who also clashed with Vettel and inherited third place when the German was demoted post-race, said his former team mate was under pressure.