My van from new wasn't supplied with a spare wheel, like a lot of cars. They probably thought there wouldn't be enough room inside a 3 tonne van to get a spare wheel 
So they supplied a tin of green snot and a 12v compressor to run off the cigarette lighter socket.
Never had to use this as i always buy the same model van and keep the good wheels off the old one when it gets weighed in.
But the other month I parked up late at night on a wet dark foul night and had the front wheels at a slight angle with the result that the pressure on the tyre from the kerb was enough to weaken the seal on the tyre and it went flat overnight.
So next day, still pi$$ing down finds the flat and realises that it's flat and not a puncture. So breaks out the compressor and connects it up, switchs on and sit inside for 5 minutes. Nips out 10 pounds in it, need 70 pound so another half hour at this rate.
Go make a coffee and come back in 15 minutes and now got 15 pound on the gauge. Gave it another 15 minutes and got 18 pound. Just enough to drive it 30 yards or so to get to the end of the drive where all the air lines connected up would reach and pump it up.
But the question is what would anyone do who didn't have a spare which would have been my next port of call but it was raining. Brand new factory supplied compressor.
PS if anyone wants it it's at the bottom of next doors pond.