Lewis Hamilton says an upgraded Ferrari engine for this weekend's Italian Grand Prix is a "step forward but not the whole amount we need".
Ferrari are taking the opportunity of their home grand prix to introduce the second of the two upgrades they are permitted this year in the hope it will improve their chances of a win on the historic Monza track.
Ferrari have the fastest car in the corners on balance, but have been lagging on the straights so far this year.
"Every little helps. Until this point of the year, even last race, we were losing 0.4secs a lap (on the straights). We have carried that deficit," Hamilton said.
"This is a step forward. It is not the whole amount we need but we knew that was the case. I strongly believe we have what it takes to win."
Hamilton and team-mate Charles Leclerc have both won one race this season, with the Briton 59 points behind championship leader Kimi Antonelli of Mercedes.
"To win this weekend, the whole collective has to come together. Everything has to flow from the beginning," said Hamilton.
"There is a first ahead of me, in the sense of if I was to win I go into new territory winning for the first time in Ferrari at Monza. It would be phenomenal.
"The pressure's high. You want to do it for the team. Many of them will come to this race. The tifosi come out in huge numbers with a passion that's unmatched.
"And my mum's here. I don't think she's been to Monza, and certainly not (while I was) with Ferrari. I wanted her to experience this and bring any lucky dust she can bring."
Ferrari's hopes of a home victory are boosted by the fact that Italian Antonelli will have a grid penalty for exceeding his permitted number of engine parts and is likely to start at the back.
Hamilton said: "There is big gap between the top teams and the rest. Kimi will start from the back but with the power he has, and the performance he has, he should slide through that pack pretty easy and it's probably why they chose this race to do that.
"So achieving eighth or sixth should be relatively easy. We have to focus on maximising our weekend and try and take the energy from the tifosi to hopefully push us to the front."
Antonelli's grid penalty was inevitable at some point after reliability problems earlier in the year meant they would need to exceed his allowance of four engines for the season.
They chose this weekend because they calculated it was the most optimal race to do it, both in terms of the effect of a new engine on a track dominated by straights, and managing their engine pool through the rest of the year.
Team-mate George Russell will also have an engine penalty, most likely in Azerbaijan in two races' time.
Antonelli said: "I am very much looking forward to this weekend despite starting from the back. I will be able to enjoy it more than I did previously and hopefully we will still be able to have a good race.
"In some ways it helps to release pressure, although I would very much rather fight for pole and start at the front.
"It makes me a bit more relaxed going into the weekend. I think this track can be very good for us but we have to take into account that McLaren, Ferrari, even Red Bull can be good this weekend.
"There are other tracks where it is possible to overtake but this one is very energy starved and there are a lot of places where you can race differently and it gives us the best chance to climb through the field."
Antonelli referred to energy starvation because the hybrid engines will be without their battery power for a higher percentage of the lap in Monza than at most races this year, because of the long straights and the lack of opportunity for recovery.
Drivers are expecting a difficult and frustrating weekend, and for slipstreaming, which saves energy by reducing drag, to become a major feature in qualifying and the grand prix.
Antonelli said he expected speed would flat-line on the straights but not drop significantly, and that the situation would be "better than many expected".
