This is the type of gauge that works best - straight line of force for the inner wheel valve.
The digital one cost $3 at a bargain store and outlasted the mechanical one, which suddenly got a leak and read way too low at age 7 years. Buy a good quality gauge and compare with a top quality one at a tire shop every chance you get.
I needed valve extenders on the outer wheels because the valve stems were too short. When the tires were replaced at Costco, I asked for long stems. They gave me medium long ones and new plastic extenders that worked very well last year. I recently found they didn't allow air tight connection with my gauge any more, due to some wear on the rubber where the gauge presses. I took one off and discovered the stems alone were long enough, so no more extenders for me. Standard valve caps, easy to take off and put on the impossible to reach inner wheel valve with a 4 inch piece of plastic tubing just the right size, held with wood dowel. See BruceMc's link to photos in his post above. I would love to have his screw on extender for airing up but haven't found one yet. I just use a chuck similar in shape to the ends on the gauges.
Of course I got rid of the wheel covers long ago. They may look good for a while but they get in the way of testing and airing up.
