Nothing I could demonstrate to you on here. But I spent many years working for a local performance shop where I got to remove and replace a lot of AN line that was petrified after less than 5 years. My test was bending it. If it didn't make any snapping noises then it was still good. But I pulled a lot of stainless jacketing off and the hose under it was was dry rotted. We also used to get a lot of complaints of the cars smelling like gas although there were no visible leaks. This is my reason using as little of it as possible. When possible, I will bend and flare to run hard lines. YMMVGot any proof of this?