I've also been considering a digital gauge, but not too hard. for reasons listed above.
I've got two manual gauges that do not agree with each other, ever. One of them agrees with the gauge on my air compressor and one other gauge, so I use that one when I can find it.
But I usually can't find it when needed and the other inaccurate one jumps out at me. It always read about 5 Lbs low compared to others so I put a piece of white gaffers tape on it with an Asterix 5 low on it.
I've got rear airbags I use to level out the rear end. I can tell when it they are outta whack by the way the van handles. On twisty turny roads I bust out the tape measure and park on a level surface and adjust PSI to make van sit flat and level front to back, side to side and the handling is vastly improved.
I want my drive axle tires to be exactly the same PSI. My LT tires go upto 50PSI, but somewhere between 42 and 45 is the sweetspot, depending on the weight I am carrying. 50PSI is too firm and does not yield the hoped for MPG gains and feels dangerous on wet roads as the contact patch gets too small.
Being able to increase PSI in the middle of nowhere is key. I often reduce it to 32psi when hitting extended periods of dirt roads for comfort and traction over washboard, but 32 psi is too low for higher speed asphalt driving.
I modified my MV-50 aircompressor into something more respectable with standard 1/4" NPT fittings and a locking chuck, and a better air hose.
