SPA-FRANCORCHAMPS, Belgium -- Honda is running updated power units on both McLaren cars at this weekend's Belgian Grand Prix.
Fernando Alonso escapes a grid penalty as his upgrades have been fitted to his previous power unit without replacing any of the six core components, but Stoffel Vandoorne will take a 35-place penalty on Sunday as a his coincides with a scheduled power unit change and features an additional small update for reliability.
Alonso's upgrade has been dubbed "spec 3.5" by Honda, whereas Vandoorne's is known as "spec 3.6" -- the original "spec 3" was first tested in Baku by Alonso and raced by both drivers from Austria onwards.
"Both Fernando and Stoffel will be running upgraded power unit's this weekend," Yusuke Hasegawa said. "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."
Honda has struggled for both performance and reliability all year, but the team received a boost in Hungary when both cars finished in the points for the first time this season. The Japanese manufacturer has said this year's power unit will form the basis for next year and it will continue to develop the current concept into 2018.
Vandoorne is now on his fifth internal combustion engine for the year, fifth MGU-K, eighth MGU-H, eighth turbocharger, sixth energy store and sixth control electronics.