Tires: Alignment, dodge ram 1500, size tires

Question
-The truck is a 2000 dodge ram 1500 1/2 ton club cab 2x4 and the sticker on the door says P225/75R16XL. The tires they installed are LT245/75R16 120/116Q. And to be honest these people were very defensive when I stopped and asked them about this problem. Without any evaluation or inspection they immediatly said that the truck was probably involved in an accident before we owned it. After I told them that we've had it since it was new, they said it was an alignment or suspension problem.
--Aaron

------------------------
Followup To
Question -
Yes they did not have the size tires I needed at the time. So they said they would give me this tires at the same cost, which are 245/75 R16 XL  which in my owners manual does not list this tire size as a recommended size, it recomends 225 or 245/75 R16 R which I think stands for regular and not xtra large like the ones I have on.-------------------------
Followup To
Question -
Can improper alignment cause tires to rub on the inside? I'm speaking specifically of a Dodge Ram 1500 running 245/75 R16. The stoppers are not long enough to catch the tire before it rubs on the metal and it has created a weak spot in the tire. But the tire technician is telling me that my truck is not aligned and that's what caused the problem.
Answer -
Aaron,

Yes, misalignment could cause tires to rub, but from your description, this doesn't seem to be the case here.  

Did you change out the stock wheels?  Or perhaps change tires?


Answer -
Aaron,

You may be in dangerous territory, so do this immediately!

Check the vehicle placard which is usually on the doorpost or in the glove box for the original tire size and inflation pressure.  Be sure to note the letters in front of the size - they are important!

The check your tires.  Again look for the letters in front of the size.

1)  If your placard say LT in front of your size and the tires say P - get in your vehicle and drive slowly to the tire store and demand they put tires on the have the letters LT in front of the size.

2)  If your placard says P in front of the tire size and the tires have the letters LT.  Well that's OK, but we need to do some calculations, so in addition to the tire sizes involved, I would need the year make and model of your vehicle.

3)  Same situation as #2 if the letters match.

Hope this helps.  

Answer
Aaron,

First, it looks like you are in safe territory from a load carrying capacity perspective.

Next is that the "XL" part of the tire size means "Extra Load".  I don't know why the vehicle manufacturers allow themselves to be put in the position that they need a non-standard tire.  This complicates getting the right tire for the vehicle.  (I also don't know why the tire industry allows this practice as well)

Then there is the tire store.  Instead of getting the right tire, they substituted and now you have 2 problems - the tires rub and your speedometer is reading low (OK, it's only 2%, but it is different). I think the lesson here is to stay away from these guys in the future.

Hope this helps.