SPA-FRANCORCHAMPS, Belgium -- Honda is running updated power units on both McLaren cars at this weekend's Belgian Grand Prix.
Fernando Alonso escapes a penalty as his upgrades have been fitted to his previous power unit, but Stoffel Vandoorne will take a 35-place penalty on Sunday as a his coincides with a scheduled engine change and features an additional small update for reliability.
Alonso's upgrade has been dubbed "spec 3.5" by the 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.