MONZA, Italy -- Fernando Alonso faces a 35-place grid penalty at the Italian Grand Prix after McLaren fitted the latest specification of Honda power unit to his car ahead of Friday practice.
Alonso will debut Honda's Spec 3.7 power unit during the opening practice session before switching back to Spec 3.5 for second session and -- if everything goes to plan -- the rest of the weekend. That way he will take a grid penalty for the new power unit at a track where McLaren are expected to struggle, giving him Honda's most up-to-date engine for the upcoming Singapore Grand Prix.
The latest upgrade is not the Spec 4 update Honda had hoped to be running by this point of the season, but an updated version of the one that first made its debut in practice at the Azerbaijan Grand Prix.
Alonso's latest power unit change means he has used seven ICEs for the season, nine turbochargers, seven MGU-Ks, nine MGU-Hs, six energy stores and five control electronics.
Asked for details on the Spec 3.7 power unit on Thursday afternoon, Alonso seemed as confused about Honda's naming system as the rest of the paddock.
"I think it is 3.7 phase. When I arrived this morning I asked what was the name of it and the situation and they said it was still undecided whether we would use race with the new engine or the current one. They have decided to take the new engine and get the penalty here. This is the 3.7 but I don't know the exact differences yet."
Parts of the Spec 3.5 power unit Alonso will revert to in FP2 are the same as the ones he retired with in Spa after he felt a problem with the internal combustion engine (ICE) midway through the race. Honda's data suggested nothing was wrong with the power unit and the same ICE will be used from second practice onward in Monza.
Explaining the reasons for his retirement in Spa, Alonso said: "I've had this a couple of times before when the sensors begin to show failings and it starts to feel wrong. That then goes to the engine immediately blowing up. After having those problems we retired the car and they checked the whole engine and it seems it is all fine. We will try to fit that engine tomorrow for FP2 and if it blows up we will change it. If it holds on we will probably keep using it."