Tires: Buying new tires for my 07 Dodge Caliber., tire placard, dodge caliber

Question
I'm buying new tires for my car and have somewhat specific needs. I'm moving across country and will be packing my car full of nearly everything I own. I noticed on the tire placard that the max load is something like 500#. I also noticed that the max load for the tires I currently have is about 1500#. I'm looking at the Michelin X-ice Xi2 tires and noticed they have a similar max load of 1500# for my specific size. I'm wondering if there is any way to go with one of the other size tires (improbable), or if you could recommend any other tire I could use with a higher load capacity, instead. I'm worried that our combined weight (300#) and weight of our belongings will be too much.

Tire size is: 215/60-17.

Thanks

Answer
Andrew,

Tire size and load carrying capacity are very closely linked.  Put another way, in order to increase the load carrying capacity of a tire, you have to go bigger - and that presents a problem.  How big are the fender wells?  And there is another problem.  Vehicles are designed to carry a certain amount of cargo and that amount is indicated on the tire placard - but tires aren't the only limiting factor.  So exceeding what is written on the placard also overloads the vehicles itself - the axles, the frame, the springs, etc.  

But I am wondering if you have misread the placard, because 4 adults would be 450#, leaving only 50# for luggage.  Surely Dodge would not have designed vehicles that way?
But you can add pressure to your tires - and that adds load carrying capacity.  My book say the placard pressure is 32 psi.  If you were to use 35 psi, you'd gain 50# per tire - for a total of 200#!