So, what's up with gauges? If you've been to a show and looked inside the cars with air suspension, you've probably seen a bunch of different combinations of switches, gauges, and other accessories- it can all be a bit confusing, can't it? Well, here's MY opinion on the matter, for what it's worth. And even though it's my job to sell you stuff, you might be surprised by my take on gauges!
Starting from the top, let's look at what a pressure gauge does in an air suspension system. Well DUH- it measures the pressure in something, right? Yep- in most cases you'll use a gauge to measure the pressure in each airbag, and possibly your air tank as well. Analog gauge packages use either single- or dual-needle gauges with air lines running from the back of the gauge out to your valve assemblies, where they're teed into your system to read pressure. Electric gauge packages use sending units to read the pressures in your system, so there will only be wires running from your valves to your gauge readout. Add air to your airbags, and the gauge will read a higher pressure- that should make it easy to set your ride height reliably, right?
Well, the answer isn't that simple, unfortunately. Air pressure and ride height aren't directly related! Think of it this way: Pretend you have your vehicle sitting level at all four corners, and your gauges are reading 80 psi in both front airbags and 50 psi in both rears (the rear is almost always a lower pressure since there usually isn't an engine back there!). Now, your friend- let's call him Big Dave- gets into the passenger seat to cruise with you to the Dairy Queen for a Blizzard. Suddenly his 400 pound butt is making your car sit lower on the passenger side, but the pressure went UP! If you even out the pressure in your system, you'll be sitting even lower on the passenger side... see how this can be a problem?
This phenomenon isn't limited to those of us with friends named Big Dave, either. If your gas tank is on one side of your vehicle, if you try to set your ride height on unlevel pavement, or if you carry items in your trunk or bed, all of these factors make air pressure kind of unreliable for setting a proper ride height.
Does this mean that gauges are no good? Absolutely not. But we don't include them in our electric air management systems to prevent new users from using them as a "crutch" while they learn their vehicle's new ride characteristics. In my opinion, it's better to install your system without gauges at first, and drive it for a few days or weeks to learn how it feels when you're at different heights. After you can dial in your ride height simply by feel, gauges can be a helpful monitoring tool in addition to your finely calibrated butt! Or, you may simply decide that you don't need 'em at all...
The great thing about selling our systems this way is that adding gauges is super easy after the fact. The Accuair valve manifold included with our electric control systems has four plugs in it that can simply be removed and replaced with fittings to run to your air lines for analog gauges or sending units for your electric ones.
If you've read this far, thanks! I hope you learned something new today. And if you skipped to the end for a summary, here's the "TL;DR" version: Gauges can lie to you, and they can make it harder for people new to air suspension to learn their system. I hope that helps you make an educated decision while you shop for your air suspension parts!