Shanghai: Sebastian Vettel said on Thursday that he had spoken to Narain Karthikeyan after the pair traded insults following a prang during the rain-blighted Malaysian Grand Prix.

Vettel, the two-time world champion, labelled the Indian "stupid" and accused him of costing him points as the action at Sepang reached its exciting climax.

Karthikeyan, who is India's first Formula One driver and races for the struggling HRT team, later branded the German "a cry baby".

"It's always a shame to lose points, but these things happen," Vettel said in Shanghai ahead of the Chinese Grand Prix, adding that he had no regrets.

"We need to move forward. It's a racing incident. I've spoken to Narain and there's nothing more to say."

Sebastian Vettel also admitted that he was having problems with his Red Bull, but insisted that his rivals should read nothing into his mediocre start to the season.

The German is going for his third world title on the bounce, a rare feat that would propel him towards the top bracket of all-time racers, all at the tender age of just 24.

But after his and the Red Bulls' supreme dominance of the last two campaigns, he has endured an indifferent start to the new season by his high standards, finishing second in Australia and a lowly 11th in Malaysia.

"Last year I had a better start, but it's only two races so far," he said ahead of the Chinese Grand Prix in Shanghai on Sunday.

"It's not ideal, but the car has a lot of potential, only we have not got to it yet.

"Malaysia was chaotic and things didn't go as planned. The car has different problems (from last year) and bigger problems. But it's only two races.

"The problems this year are very different, maybe bigger," the German said, without going into details.

"We have a very competitive car, we just need to get it working properly," he added.

"We can't get to the real potential of the car and we can't get the balance of the car quite right.

"When we get this right, we will be in a much better position."