James Calado says Ferrari needs further GTE Balance of Performance tweaks, and believes his Silverstone World Endurance Championship victory was earned on "strategy more than anything else".
Calado and Alessandro Pier Guidi scored Ferrari's first GTE Pro win of the 2018/19 WEC superseason on Sunday in their #51 AF Corse-run 488 GTE.
The reigning class champions - who were boosted by a small pre-weekend power increase for the Ferrari - took advantage of two full-course yellow periods and a safety car to work their way up the order in a race where they lacked the outright pace of Ford and Porsche.
Calado was vocal about Ferrari's deficit to the pacesetters in the Le Mans 24 Hours and, asked by Autosport after his Silverstone win about the 488 GTE's performance, said more work was required to equalise the class.
"It's lacking in straightline speed," he said of the Ferrari.
"In qualifying we tend to see [a deficit of] 7km/h or 8km/h to the fastest guys.
"We struggled to pass the Am cars, which makes our racing really difficult. We do need more straightline speed.
"I'm hoping due to our lack of performance we should get something."
Calado and Pier Guidi qualified ninth fastest of the 10 GTE Pro cars in the field at Silverstone, with an average time 1.3 seconds down on the pole-winning Ford GT.
The Briton revealed a wrong set-up choice had exacerbated matters, but said trying to take advantage of any full-course yellow periods had been Ferrari's tactic from the outset.
"The briefing we did [on Saturday], it was a good couple of hours long and we got the set-up wrong," he explained.
"Obviously we rectified that, the car was handling fantastically.
"We knew on pace alone we're not quick enough, so the plan was to save as much fuel as we could and try to get an advantage in terms of strategy, doing something different to the others. That paid off.
"Ford were unlucky with their strategy, they were very quick. I think they were in the [1m]57s at times, which was obviously impossible for us."
The sister #71 Ferrari of Davide Rigon and Sam Bird was also running strongly until it was involved in an incident with the #17 SMP Racing BR1 LMP1 car, which left it with a puncture and severe bodywork damage.