Red Bull driver Max Verstappen will start from the back of the grid at Sunday's Italian Grand Prix after Honda confirmed that his car will be fitted with an upgraded power unit this weekend.
The upgraded engine has been scheduled into Honda's development plan since the start of 2019, but will take Verstappen over his allocation of engine components for the year, resulting in a grid penalty. Known as the "Spec 4 PU", it was also fitted to Alex Albon's Red Bull and Daniil Kvyat's Toro Rosso at Spa-Francorchamps for Friday practice, resulting in grid penalties at the Belgian Grand Prix for those two drivers.
With Pierre Gasly's Toro Rosso also receiving a Spec 4 engine in Monza -- and the resulting grid penalty -- all four Honda-powered cars will use the updated power unit for the first time in Monza.
"We now go from one classic track to another, from Spa to Monza for the Italian Grand Prix, which is the last race in Europe this year," Honda technical director Toyoharu Tanabe said. "It is one of the highlights of the season and also the home race for one of our teams, Scuderia Toro Rosso.
"From a PU point of view, the main development is that we plan to run the Spec 4 PU with all four drivers for the first time, after just Albon and Kvyat ran it in Belgium. For their first race with Spec 4, Gasly and Verstappen will therefore take grid penalties and start from the back of the grid, but we believe they can still race strongly on Sunday.
"We gathered useful data in Spa, which we have used to make changes to PU settings and calibration in preparation for this race. We will try to maximize the potential of Spec 4 and hope to get another positive result, maintaining the momentum we gained in Spa."
After four years of struggling to match its rivals in F1, Honda has made good progress in 2019 since joining Red Bull as its engine supplier at the start of the year. Speaking at Spa-Francorchamps, Red Bull team principal Christian Horner said the performance of Honda, Mercedes and Renault was now starting to converge, with only Ferrari still holding a significant advantage over the others.
Monza is the most power-sensitive circuit on the calendar, meaning extra horsepower is more valuable for lap time at the Italian circuit than at any other track in F1.