[siverson]

While I'm all for making our old not-so-safe cars safe (compared to modern cars), I do not understand the 5-year expiration on aftermarket seat belts. They all have a tag with the expiration year on it, and PCA, NASA, etc do check this diligently during tech inspections - probably because it's easy. I drive my car about 3,000 miles per year, and my now 5 year old belt still look great, but to get a new expiration tag is going to cost me $600+ ($300+ per side).

Why are originally lower quality factory belts that are now now 35 years old OK (no expiration), but more modern 5-year old replacements are not?

Is there any scientific reasoning that the belts become significantly weaker after 5 years?

I suppose an expiration makes sense, but 5 years seems much too often to me. I'm happy to spend money to make our hobby safer, but I'd rather put the $600 towards a HANS device I don't have.

-Steve