So yesterday on the way into work, I tried three air pumps at different service stations:
- broke - you can't tell until you park next to the unit and see a quarter stuck in the slot
- $1.00 - low pressure and not enough time to add more than about half the pressure needed
- $0.50 - strong pump but half the time, not enough to bring all four tires up to pressure
So I was out $1.50 and three stops and still didn't have enough pressure.
I went to Harbor Freight and was looking at the $60, 3 gallon, 120VAC unit, planning to use the inverter in the back of my car. But one of the clerks turned me on to a robust, 12V unit with pressure gauge at less than half the price. Problem solved!
After plugging in and starting, the hose screws into the valve and you can watch the pressure increase. Once it looks to be right, turn off the pump to read out the pressure without the pulses and then unscrew the hose. As expected, it gets pretty warm from compressing the air but it does the job very nicely. Best of all, it will stay in the trunk so when we have to use the full-size spare, I can bring it up to operational pressure and move on down the road.
Bob Wilson