F1: Ferrari believes passing Mercedes in Malaysian GP was unlikely

Vettel took the lead of the race by staying out during an early safety car period, while Mercedes' Lewis Hamilton and Nico Rosberg - who were running first and third - made early pitstops.

Both Mercedes drivers lost a significant amount of time passing slower cars after the restart, allowing Vettel to build a lead that Hamilton then couldn't close in the final stint of the race.

"I think we were probably a bit quicker than Mercedes in race," said Allison.

"We saw that when Mercedes were in traffic that was slower than them, they found it hard to get past.

"So if you're maybe a tenth or two tenths quicker, which is maybe what we were, than that is super hard to turn into an overtake, super hard to overtake on two cars."

Allison believes that had Ferrari called Vettel in under the safety car with Hamilton and Rosberg, then it would have given Mercedes more options to cover off any threat.

"[Had Vettel stopped] They would have had the opportunity to split their strategies and at least beat us with one car," he said.

"The safety car presented us with the opportunity to get past in a relatively painless way."