Most French airlines will be in BAR, and 1 Bar is about 14.5 psi. HERE
's a handy online converter so you can work it out in advance.
You might intially stand around in French service stations looking for an airline, but if you do, then look for something like a small WWII sea-mine with a handle on the top and painted red. It's PROBABLY the airline, and you can carry it to your vehicle (but don't yell at me if it turns out to be the fire-extinguisher). You'll need to put it back on its cradle thingy though so it can fill up again.
Other places you can fill up are any garages, but you'll need to go to the workshop door and ask, they usually have an airline around there somewhere.
Happiness has 125 cc