Kimi Raikkonen as fast as F1 team-mate Sebastian Vettel - Ferrari

Allison can only recall Vettel making one error this season, when he ran wide at the final corner on lap 36 of the Bahrain Grand Prix, damaging his front wing and forcing an unscheduled stop.

Raikkonen has had a tougher time of things, particularly in qualifying, resulting in the fact he is 59 points adrift of Vettel heading into this weekend's race in Hungary.

Ferrari has sympathy for Raikkonen

Asked by Italian publication Autosprint to assess Raikkonen's season, Allison said: "There's no speed difference between he and Sebastian.

"Sometimes Kimi is quicker, other times it's Seb.

"The difference is Sebastian never, or almost never, makes mistakes.

"This year only in Bahrain have we seen after all, that he can make mistakes.

"But besides that weekend, he has practically never made any errors. Kimi instead, especially in qualifying, has had a few more slip-ups.

"I'd say the same thing if Kimi was here, and I think he would accept it.

"Sometimes you just need a small mistake to ruin a weekend, but the speed is there. Kimi knows that too."

Allison is also convinced Ferrari can again close the gap to Mercedes after falling away of late to undermine the positive start made to the year, with the highlight being Vettel's victory in the second race in Malaysia.

He has suggested that success "perhaps" came too soon and raised expectations but he has no doubt Ferrari will rediscover its form.

"You certainly can't refuse a victory when it comes," added Allison.

"The Malaysian Grand Prix was an incredible day, getting back to winning ways has given us a great push, and now I can't wait to re-live it again.

"If I look at what we have done since the beginning of the season, I see our work has produced good results.

"We have improved by 1.5 seconds per lap thanks to the development done on both the car and the power unit.

"If I have to bet on what's going to happen in the second half of the season, then I believe we'll reduce our gap to Mercedes and that we'll do better than Williams."

Translation by Michele Lostia