After doing some reading on truck tow ratings, I just found out that a new standard was created a couple years ago, SAE J2807 that is supposed to normalize the ratings across manufacturers.
As has been said many times, in most practical situations you realistically could only use 70-80% of the manufacturers tow ratinsg and still have a decent handling vehicle. This proves it.
Example: My 2009 F-150 super crew was rated at 11,300 pouunds of towing. The F-150 today with a more powerful engine is rated at 10000 pounds. And ALL the manufacturers played loose with how they came up with their tow rating.
Here's a good article I found that explains it:
http://www.automobilemag.com/feature...ss_sniff_test/