Stoffel Vandoorne looks set to start his home race in Belgium from the back of the grid due to various penalties for changed engine components.
Both McLaren drivers will run Honda’s updated power unit for the Belgian Grand Prix at Spa-Francorchamps; Fernando Alonso will use spec 3.5 and Vandoorne spec 3.6.
While Alonso has not picked up any grid penalties for the Belgian F1 round, Vandoorne’s car has been fitted with new MGU-H, TC, Control Electronics, Energy Store, MGU-K and ICE components.
He is on his eighth MGU-H and TC of the season, sixth Control Electronics and Energy Store, and fifth MGU-K and ICE.
This means he will be handed a 35-place grid drop from wherever he qualifies at Spa for his home event, and ostensibly start from the back of the pack.
“Both Fernando and Stoffel will be running upgraded power units this weekend,” explained Honda boss Yusuke Hasegawa.
“Unfortunately Stoffel will receive a grid penalty at his home grand prix, but it is important for us to introduce updates as soon as they are ready.
"It is positive that we have been able to introduce this next step forward so quickly, and we will continue to introduce updates throughout the remainder of the season.”
Vandoorne is heading into his first home F1 race at Spa, following on from a difficult opening half of his rookie season.
The 2015 GP2 champion has scored just one point so far this year, at the last round before the summer break in Hungary.
McLaren confirmed on Wednesday that Vandoorne will remain at the team for the 2018 campaign.
