Really tough to know as we haven't read the manga in Japanese lol. But looking at the many times and several times statements in the Strength Checker, these two come to mind:
Chapter: 366 (DBZ 172), P9.4
Trunks: “It-it’s hot…The air is thin too…And gravity is many times greater…”
Chapter: 482 (DBZ 288), P9.3-8
Context: Piccolo finally catches up to Gotenks
Gotenks: “You’re slow. So you finally got here? Besides circling around the Earth several times, I even took a little afternoon nap. [ ] Fuffuffuh…So you can’t tell just from my speed just now? My super-duper incredible power…! …Which is to say that the test is over, and I’m going to go take care of that annoying Majin Boo right away”
I can't be assed rn to look into the raw scans what word was used here for both instances. The gravity is 10x and Trunks said it's many times greater... Though even if the word Sūbai was used, which I don't know and don't think it was, it may just be Trunks doing a rough guess.
Gotenks from what I could count, circled the Earth 4 or 5x and I think the word Sūbai would fit here as Herms translated that as "several". The other statements with many or several in the strength checker are ones we can't quantify the gap, and there isn't a "many times" or "several times" statement in the strength checker at least, when Piccolo talks about his power post youth recovered. If anyone hasn't until a few hours, I'll look into the raw scans later, but we can only know the instances it was likely used looking at the strength checker as a basis for which instances this word was likely there, otherwise no one but those who understand JP can read all the manga to check that and even those who know wouldn't read looking for the word Sūbai unless there's a transcription of every dialogue from the manga and you can just click "find in the page" lulz. But just knowing what connotations the word have in Japan from a native member should be already enough imo.