I'm not sure this is entirely correct. The traditional requirements for becoming a licensed engineer (at least in Colorado and in most other places) are you need 8 years. These 8 years are comprised of:
a) Bachelors from an accredited university (whether it takes you 2 or 25 years, it only counts as 4 years)
4 years working under a licensed engineer doing relevant engineering work, for instance, I work at a firm that does a lot of material testing and also other engineering, I have heard lab material work does not qualify as relevant engineering work
c) If a masters is obtained, that will count as ONLY 1 year which will allow you to only need 3 years of working under a licensed engineer (I'm not sure what the case is with a PhD to be honest)
Also, before you are allowed to take the PE exam, you will have to go in front of a board that will review all your preeq's to make sure that you are eligible to take the PE.
Hope this helps or at least informs... 8)