"We finally quit when mu buddy's vintage spare exploded in his garage. Still a good method if you ask me just use a fresh spare 
."
Well… I’ll tell you what I think about that.
First…. H8PVMNT… that post dropped your I.Q down about 20 points! LOL….. Somewhere just above a retard.
You went from “Master Tweaker”, to “Master Twit”.. LOL.
Secondly, I would NOT want to pump up my spare 2.5 times above the maximum rated – not only because of the obvious danger of exploding and causing some serious injury or damage, but also because the stress may make the tire structure fail prone.
Thirdly, buying the necessary connectors and hoses would cost more than a 5 gallon compressed air tank.
And, lastly…. I would have to witness a 33x12.50 tire at 120 psi produce enough volume of air to air up 4 tires from 8 PSI to 25 PSI… I don’t think there is enough volume of air (cubic feet of air) in that tire. You would need about 2 cubic feet of air, which is about 15 gallons, or 3 each 5 gallon air tanks, filled to about 150 PSI each.
Of course, anything is possible on 4-wheeling forums, and I could be sucking air somewhere. 
Gnarls. 
Gnarls you doad. Read the post brainiac
!
I used a 10 ply spare. The 10 ply 235/85 r16 load range E spare had a max inflation of 120 psi.
I would not do this with a 33x12.50 6 ply rated for 35 psi max that would be asking for it. If that's what you got out of that you
should think I was a reetaard! I don't even blame you, just put on your specticals.
And just for clarification for the calculator police, I don't
think it will top off 4 tires from low pressure to low-mid 20s psi, it
DID top off 4 tires from trail pressure to low-mid 20s psi. I even reseated a bead with it a time or two with the help of a ratchet strap. Compressed air is compressed, so if you use a load range E for a spare maxed out you get a lot of air out of it. I don't make a habit of posting speculation.
Oh and 300K, don't be doing this with your 6 ply re-treads spare, you will blow your head off! 10 ply spare, 10 ply spare, 10 ply spare, load range E max psi 120...
Now you've gone and done it. I have burned my Brussel sprouts because I had to reply.
