Honda has spent seven of its Formula 1 engine development tokens on an internal combustion engine and turbo compressor update ahead of this weekend's Belgian Grand Prix, Autosport has learned.
The Japanese manufacturer's main focus is to improve combustion efficiency so a large chunk of the tokens have been spent in that area.
The remainder have been focused on the turbo, which follows a two-token spend on that component for Canada, with the target of improving harvesting efficiency.
When Honda introduced that update in Montreal, it used some of the exhaust power to improve the efficiency of the turbo and that in turn decreased the output of the engine.
An update was introduced at Silverstone to try to recover that loss and it is hoped this latest update will bring output back up to the original level.
Jenson Button and Fernando Alonso will take the fifth element of all six engine components this weekend but as that is within their respective allocations, there will be no penalty.
While the lap time gains from the update may not be dramatic, it is hoped the drivers will be able feel the difference and the developments will help with Honda's plans for 2017.
Autosport understands ExxonMobil has brought a new fuel to tie in with Honda's latest update.
Honda has now used 29 of its tokens and has three remaining.
The Japanese manufacturer's motorsport chief Yusuke Hasegawa previously told Autosport the manufacturer plans to do a further update later this year, but that prospect remains unclear following its largest in-season token spend for Spa.