I guess I mis understood the thrust of the question "pump to keep in the car".
if you are going to use a Silca or SKS pump to inflate car tires - you'll be pumping a long time.
also with car tires - at least modern ones, if they lose pressure you probably have a leak in which case you're much better off with a can of goop that will get you to the tire shop.
There are some really wonderful vintage Dunlop pumps that are high volume, foot operated units. I've never taken one apart so have no idea what the availability of replacement seals, etc might be. See below.
If on the other hand you want to inflate bike tires - well, there are many good suggestions above. I personally like the Silca b/c they are fully rebuildable and can thus last "forever". Which is a lot more than can be said for a $20 electric "device" from harbor freight or Walmart.
Mark Petry
Bainbridge Island, WA USA
