I run 3/8s and my tank at 175psi with a level ride ecu....
What I’ve gathered for be the change is that people went with 1/4 for ease of install by thier shops but are fed the line that “unless you are trying to hop the car 1/4” is fine” lol. Then that became the normal thing to REPEAT as the internet does.
I went 3/8th and dealt with the extra work to route the lines cause I watch too many vids and seen cars inperson with 1/4” line and the dump and lift was too slow for me.
My fronts are still to slow for me to be honest because the braided leader lines all come in 1/4” so the last 12”s that feed my front bags get bottled down and you can see the cars front lift and drop slower. I still need
To make some custom ones- I’m planning to make them with 8- an lines.
Edit: btw - there’s only like 2-3 members that are active with air ride lol- so you won’t get many current/first handed responses, lol. 85% of members are- “rear sway bar, tires, EQTEQTEQT ots, dogbone mount - performance car build done.
It’s replaced the “I got bags, wheels and now my show car build is done” era with modern vws, lol