I wanna buy a titan LE 2005 but I am unsure if it will comfortably tow a 1500lb bumper pull horse trailer with 1-1000lb horse from east coast to west coast!"? And I might have a bed full of stuff I would say 500lbs in my truck bed also to consider? Can it do it or do I need a 3/4 ton truck?
The question is, what is your definition of comfortably? If it's a V6 or V8, it is certainly capable but you will know you are pulling something and you will have to change your driving habits because the truck will perform and stop differently.