Honda is still evaluating how to best exploit its remaining development tokens in the near term future, and will therefore stand pat on the power unit front for this week's in-season test at Barcelona.
With 14 development tokens still up for grabs and a desire to push forward with increasing the performance level of its engine, the Japanese manufacturer was expected to implement a series of changes and upgrades as soon as this week.
But Honda F1 boss Yusuke Hasegawa has said that the evolution process is still under evaluation.
"I haven't decided yet," he explained to Motorsport.com.
"Although we are developing all the time, if we don't care about tokens we are ready to update.
"But I need to decide the tactics about which grand prix we have upgrades, so I cannot tell yet. We have no concrete plan."
Hasegawa acknowledged however that a few changes would be put to trial at the Circuit de Catalunya.
"There is not a big hardware update, but there are some control items."
Upgrades, partial or substantial, are now expected for Canada where new fuel is expected to be introduced as well as a new cycle of power units for both McLaren's Jenson Button and Fernando Alonso.
"We don't need to use tokens for the fuel updates. Any time that it is ready, if we change the fuel we have to change the mapping: so also it is reasonable and effective to have the update timing to this as well."
"We haven't decided when the next engine will come but first we need to check Fernando's engine is okay for Monaco.
"But we think it is fine. It was an unexpected mode switch that killed the engine. We don't know the cause of that happening, but we think the engine itself can be used for the next race. We need to check the situation."
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