drafalske

Not sure how it would relate to our pickups, but semis do roughly the same thing. Depending on the tractor of course, but usually 50psi in the rear bags means ya gotta slide the tandems up a bit to take weight off the tractor. Sounds like a good time to load up as heavy as *safely* possible (verify at a scale) and check your pressure. You could then derive an equation to figure your weight based on any given air pressure. Good luck<br>-Dave

js

if you put a gauge on your lines between the height regulater and the air bags it will tell you your air pressure in the bags. then if you record the presure with no load and then load up and scale your rear axle you will know the air pressure for that weight. if you could max out then scale you will know the pressure for min. and max. load on that axle. anything inbetween is legal and over time you can look at the gauge and be pretty close in guessing what you have on.

wannadiesel

There are on-board scales for heavy trucks that work by reading the air bag pressure. You need a full air suspension system for this to work properly, but I like js's suggestion, should get you in the ballpark.

y-knot

I like the thinking of your question, but i don't think it translates . I run air bags and there isn't a any corallation betwen air pressure and load. First off all bags seep air, they are designed too, so you really couldn't accuratly tell. 4-6 psi isn't a realistic number to run, I will run between 25-70 depends on load and road. if the system was compleatly sound and temperature, ect. all taken into account, maybe? What I did to make the ride abit better was to install a small (4&quot; x 12&quot; ) ss tank in line with the bags. This way when the truck hits a bump, and the suspension compresses say 2-3&quot;, there is a pressure spike ( bags are 8&quot;x 10&quot; and at say 30psi,suspension travels 2&quot;, bags now 8x8&quot; and pressure spikes to 65psi(just for that instant), now put your small tank in line with the bags, and you give the system a place to expand, same bump now pressure only spikes to 35 psi.