[semi-extrinsic]

From a 2-minute google search, it looks like both are ~10 psi pressure difference (psig). The numbers I found were 7-10 psig for a plane and an estimate of 17 psig for the soda can. So they're quite similar and it's not a stupid question.

[e12e]

One of us appear to be wrong :-)

I was just coming back to edit my reply to say that the difference appear to be 0.5:2, or the soda can holds roughly 4x the difference.

Ah, but I'm tired, maybe I read/thought wrong.

[semi-extrinsic]

Well, the 17 psig number I found was an estimate, so if you found the soda can holds about 4*7 = 28 psig, I'd say we agree.