Regulate is a synonym of Settle. Settle is a synonym of Compound. Compound is a synonym of Agree. Agree is a different concept from Refuse. 
Powerful is related to Motor. Motor is related to Vehicle. 
Regulate <--Synonym--> Settle <--Synonym--> Compound <--Synonym--> Agree <--DistinctFrom--> Refuse 
Powerful <--RelatedTo--> Motor <--RelatedTo--> Vehicle 