Well I have 3 of these just because I always wait to inflate my tires that wear out so much in winter. So yes, going from 20psi to 36psi takes quite a while, about 8 minutes. But it works great. So instead of spending 30 minutes outside pumping up those damn tires, it now only takes me 10 minutes to buy 3 of them. (not 4 as a hoop is faithful to me and doesn't deflate lol)