TOPIC: PMBOK Guide - Can we trust older editions for future PMP Exams?

I have a copy of the 4th Edition in my book collection. I'm wondering if it's still useful for the current PMP exam or if I will need to purchase the 6th Edition. Another option might be to leverage my PMI membership for access to the latest book (although, I prefer physical books versus digital versions). Does anyone have any suggestions?

Juan,

The answer is quite simple: If you use an older version of the PMBOK Guide, THEN YOU WILL FAIL YOUR EXAM! So spend the money and buy the current version.

Oh... and that goes for all your exam prep products: Always use training materials that are based on the current PMBOK Guide and updated to the most current exam content outline. Use anything else and you will fail. Period.