If you are asking why 2 load index numbers are given for one tire, the lower
number is specified if the tires are run as pairs or "duals".
Commercial tires usually have 2 load indexes as they are often run on dual
wheel axle trucks.
Found some info in this thread:
http://www.expeditersonline.com/trucking/Truck_Topics_1/The_Tool_Box_-_Tires
_printer.html

it's regarding semi's, but the concept is the same.

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Dave Mcneely
Sent: Monday, October 01, 2012 10:24 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Commercial tire?

I run 195R14 C  tires front and rear.  The load index on the sidewall is
106/104.  I am unsure why this is given as it is...