Correct me if I'm wrong but didn't Tien say that Goku, Vegeta, and Trunks were pretty close together in terms of power? Piccolo said Vegeta wasn't that far ahead of Goku and we have Tien saying they aren't that far apart. So I don't have them very far apart. I have
Trunks being 90% of Vegeta
Goku being 95% of Vegeta
Tenshinhan said Goku shouldn't be that different from Vegeta or Trunks, so they all have to be fairly close together, and we know Goku is right on Vegeta's heels. Vegeta couldn't outrun Trunks on their way to Gero's lab either, so their gap can't be giant or he'd have easily done it. I'm good with a 92/96/100 scheme, give or take.
Vegeta is noticeable stronger, but they are still not far apart according to Tenshithands and Vegeta not being able to dish out his son and calling him annoying for that. Trunks is 88% of Vegeta in my book.