'02 Mitsubishi Diamante Timing Belt Replacement at 60K or 100K?



I wonder why replecement timing belt interval for '02 Diamante is 60000 milles for some states but 100,000 for selected states (CA, Massachusetts, Vermont and Maine) ?

Some states required the 100,000 for any parts related to the emissions.  It may be a different belt on that car or they may have just changed the recommendation and hoped they last that long.