clare wrote, on Mon, 07 Dec 2015 18:38:42 -0500:

A 12 volt compressor or a good manual tire pump is a
lot better than canned air

Probably true.

1. The advantage of canned air is that sealant is often included,
and it doesn't require electricity and it's small but it
goes bad over time.

2. The advantage of a compressor is that it doesn't go bad over
time but it's much larger and it requires electricity (which
is usually ok except the cigarette lighter is FAR away from
the rear tires if you keep the wheels on the car). On a bimmer,
the battery is far from the front axle. On most cars, it's
the opposite, but you still have that problem.

3. The advantage of a hose that goes from one side of one axle
to the other side of the other axle is that it's small, it
never goes bad, but it does suck some air out of the other
three tires. If you're lucky, you can suck air out of someone
else's tires!

The main disadvantage is that you have to make it out of
a hose and two chucks, one of which has to latch on and
the other has to have some way of shutting off (which most
chucks do). The biggest problem is that the chucks are usually
pretty big, so that necessitates a bigger hose than you want
(or need) to store.

My plan is to build a long thin hose, with two hoses on the end
that are thicker which contain the two chucks. Dunno if it would
work though, as I don't know how much air you have to scavenge
from three other tires to fill up one tire.

Of course, in a parking lot, there are lots of tires ...