I gotta start making up stuff to sell on ebay!
You have a flat for a reason and no ammount of air from every parked car : in the kmart lot will help!:

 

im def in the wrong business

 

So you end up with a near empty spare and a tire that will stay up just long enough to drive away from the good ole G M stealership.

 

lets see, flat tire has 0 psi, full tire has 50 psi, now both tires are at 25 psi....still gonna be darn hear flat.

Even if he got the spare from to 25 and his flat tire to 25, if he then split the difference from a second one, he'll get what another 3 psi from a good tire?

The best I think you can do, if you took a "little" from each tire, assuming all tires had 50 psi, is what 30-35 psi?

 

Actually, the concept is sound, but for a few bucks more you can buy a cheap 12v portable compressor that would be a lot more useful.

 

wow. a coil of cheap air hose and two chucks.

I'm with Tom....id rather have a portable compressor. You can blow up air toys at the beach, too.

 

Or the bedroom.

 

Or the bedroom.

You have 12V in your bedroom ?

 

...

I forgot, take a couple of these any you will be fine...


http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=130125188362

 

why not just use the spare

 

why not just use the spare

What if you already have - or find out it's as flat as the tire you are airing up? Still, I think a small 12v compressor is the way to go. It may take a while, but it will "git'er done".

On gas engines, they also make a device that replaces a spark plug and will inflate a tire (using outside air - not air from the engine). I used one with an old Blazer I had.

 

A small plug kit would be a good thing to have in addition to the compressor :grd: