As with previous 2023 events it means that car set-up is frozen after FP1 as the field heads into qualifying, and any changes thereafter will trigger a pitlane start for the sprint and the grand prix itself.
The teams already have some experience of the new format, which was used in Azerbaijan and Austria.
However, it will be particularly challenging at Spa, where cars are especially sensitive to downforce and drag levels, as well as ride height, with the compression at Eau Rouge creating a compromise for the latter.
Usually at the Belgian venue engineers have three practice sessions during which to experiment, while eyeing the straightline speed of their immediate rivals, before settling on the best solution for qualifying.
This time they will have just a single session after which they have to make those crucial set-up calls.
If they get it wrong their cars could be out of kilter for the rest of the weekend, leaving their drivers either unable to defend on the long run up from Eau Rouge and Raidillon, or lacking speed through the corners on the rest of the track.
Teams often react to where they think their cars are likely to start, for example when those with grid penalties have erred towards less downforce and maximum straightline speed in order to help their passage through the field.
The alternative approach is to focus more on the twisty second sector, where extra downforce pays dividends.
Source: Autosport