question about car seat expiration dates

[glrdap]

Hi,
I keep reading posts that mention that carseats expire 6 years after the manufacture date. First of all, am I crazy or did it used to be 7 or even 8 years? The convertible carseat that I just started using for my baby and which I am looking into replacing was bought for my oldest who is now 8 (he was born in April '99 and I probably bought the carseat that winter) and it says on it that it shouldn't be used after December 2007!
My second question is - what exactly happens to the carseat at 6 years and a day? I understand that safety standards are always being upgraded and that there is wear and tear on the parts but how rigid a deadline is the six years number?
Thanks for clearing up my confusion!

[tjham]

You probably have a Fisher Price Safe Embrace. Love those seats! They were (are) good for eight years but most seats have been (are) good for six years.

Some newer ones coming out now are again good for eight years. It can be confusing. You have to read the manual or look on the seat to be absolutely sure.

http://www.windsorpeak.com/dc/dcboard.php?az=show_topic&forum=13&topic_id=44208&mesg_id=44208&page=3