The Ford GT has been hit with a reduction in fuel capacity, with adjustments having been made to three of the four GTE-Pro manufacturers ahead of this weekend’s WEC Six Hours of Spa.

The FIA confirmed on Tuesday that the Silverstone class-winning Fords will have a four-liter reduction in fuel capacity for the second round of the season, with increases given to both the Porsche 911 RSR (+3 liters) and Ferrari 488 GTE (+1 liter).

The changes come amid a frozen Balance of Performance for the GTE-Pro class, which utilizes a baseline BoP for the opening two rounds prior to the full rollout of the new automatic system beginning at the Nürburgring in July.

According to ACO Sporting Director Vincent Beaumesnil, fuel capacity does not form part of the auto BoP.

Beaumesnil said the adjustments are aimed to bring parity to stint lengths. It’s understood the Ford was able to go one lap longer than the competition over some stints in last month’s season-opening round.

Ford WEC team principal George Howard-Chappell told Sportscar365: “Obviously it’s always been a case of the stint length and the refueling time is attempted to be equalized.

“If it wasn’t right at Silverstone, which I guess it wasn’t because there’s been action, then it’s logical that it’s equalized.”

BoP changes, meanwhile, have been made to the GTE-Am class, which is not subject to the automatic process.

Both the 2015-spec Porsche 911 RSR and 2016 Aston Martin Vantage GTE have been given a 10kg weight break, with the Ferrari 488 GTE handed a 10kg weight increase.

The Porsche is now mandated to run at a minimum ride height of 45mm.

It marks the first BoP adjustment for the class this season, which accepts GTE cars from both 2016 specification as well as 2015 and older, under the two different sets of technical regulations.