There is a concern that the increased fuel capacity allowed for the 2017 season per race is not enough and could lead to fuel saving races where there is notably higher consumption.
To allow for the higher downforce introduced in the 2017 aero regulations, teams will be allowed to run with 5kg extra fuel, making a total of 105kg for the race. However, reports have come out from winter testing that this is likely not to be enough in some cases.
The German publication Auto Motor und Sport has reported that with 10% more air resistance from the wider cars, and a reduction of 20kph on the straights with longer spent of full throttle, fuel consumption has been higher than expected from numbers calculated over the winter. It just so happens that two of those marginal races are at the start of the season, although under the new regulations we haven’t seen a team run out of fuel so far, given that consumption is carefully monitored.