Oh, they have the volume, but a slow leak too quiet to notice wouldn't have the flowrate, and a sudden release of a sufficient flow rate would be noticeable.
So - if you are smart enough to notice that the tank is leaking when the noise tips you off, and open a window, you will be fine as far as suffocating goes.

_________________________
- TJ
2001 Xterra '03 VG33, SE 5 spd, 305/70/16's, Revolvers, UBSkidderz, Doubled AAL's, 3"SL/2"BL, winch/bumpers, skids, sliders, OBA, Snorkel, pine stripes....
Friends don't let friends drive stock.
http://www.gifsoup.com/view/501230/tj-tackling-crawlers-ridge-o.gif