Sidney, my TV has the same brand and size of tires that yours has any my 5er is very similar. I've got 21K on the truck - about 1/3 towing and tires are performing well - don't even show wear. I do have a six-tire rotation done each 6-7K interval - I do think rotation definitely helps.
Don't know why your tire dealer is recommending a change, unless your tires are worn and need replacing. My '03 Dodge had Michilins and I was disappointed at first when the '06 did not come with them, but I really can't complain.
The fellow that bought my '03 still hasn't replaced the tires as yet and they have over 80K on them, so, if you need new tires, you may want to consider Michilins.