Fernando Alonso will run Honda's more-powerful 'spec 3' Formula 1 engine in this weekend's British Grand Prix, but will take a grid penalty because of a component change.
Honda discovered a problem with Alonso's MGU-H in Austria and so reverted to a complete old-spec power unit for the remainder of the weekend to save time.
For Silverstone, he will go back to the 'spec 3' engine that was used on the Friday in Austria, but with the old MGU-H that he ran from final practice in Austria.
There will also be a new energy store will be fitted. As that will be his fifth of the season, he will incur a five-place grid penalty for Sunday's grand prix.
Honda anticipates further changes that will incur more penalties, but will only decide after Friday's second practice session.
Given McLaren-Honda is expected to struggle on Silverstone's high-speed layout, it could tactically take further penalties this weekend rather than at the next race in Hungary, which offers a stronger chance of a good result.
The MGU-H that failed in Austria was a countermeasure part that was drafted in following a string of failures earlier in the season.
Honda sent the part back to its base in Japan and has been working on finding a fix, but with Austria being back-to-back with Silverstone it has been unable to get one ready in time for this weekend.