McLaren are confident their new car is good enough to be competitive at all circuits after Jenson Button won the season-opening Australian Grand Prix.
The team's cars have struggled in recent years, compared with world champions Red Bull, at tracks with more demanding corners than Melbourne.
But McLaren technical director Paddy Lowe said pre-season testing had demonstrated the car's versatility.
"The car has got good all-round performance," he said.
The Malaysian Grand Prix this weekend is held at Sepang near Kuala Lumpur, a circuit that would have been expected to favour Red Bull over McLaren in recent years.
But Lowe pointed to McLaren's strong performance in pre-season testing on Barcelona's Circuit de Catalunya, the most demanding track in Formula 1 of a car's all-round capabilities, as evidence that McLaren should be strong again in Malaysia.
"Malaysia will be interesting, but I'm not feeling too worried about the fact it is a different circuit characteristic to this one," Lowe said.
"Our performance in Barcelona was quite encouraging in that aspect, Barcelona being a classic, high-speed downforce circuit."
Lewis Hamilton finished third in the other McLaren after starting the race from pole position ahead of Button.
Qualifying has been another area of weakness for McLaren in recent years.
Lowe said: "I think the qualifying result is the most pleasing at this point because that is indicative of your qualifying pace, which is what you use to establish race wins and control from the front."
Red Bull, for whom Vettel took 15 poles from 19 grands prix last year, qualified fifth and sixth, Mark Webber lining up ahead of the German world champion.
But team principal Christian Horner pointed to the fact that Webber had been the fastest driver on track once he had fought his way back from a poor start into fourth place behind Button, Vettel and Hamilton.
"That gave us a lot of confidence," Horner said.
"On a sample of one, it looks close. We knew from winter testing McLaren were competitive; we've seen that this weekend.
"I think our race pace was every bit equal with them.
"Neither of the drivers has been totally happy with their cars here. We know where we need to improve.
"We have plenty of things in the pipeline [to make the car faster] so we take an awful lot of positives from a podium and a fourth-place finish."