I've used it on various cars for long periods of time. As long as the temperature range is wide enough, it'll suffice. Of course, I'm not the only person in the universe who uses it.

0w, however, is scary on engines that have too many miles on the clock and looser tolerances. Of course, I've never run an engine on oil that thin, so I can't say how dangerous it'd be... so I'll just state that it scares me.

Others, however, have run 0w40 Mobil 1 here for years with no problems.