Tires: load range D vs. E, proper inflation pressure, inflation pressures

Question
Hello

I purchased a forde350 1997 used from the BP/ARCO used last year.

The van has load range D tires, but the stores tell me I need load range E tires.

My wife complains that the van drives like a boat. Do you think load range E tire would help?

Answer
Mike,


There is no question your vehicle needs Load Range E tires.  But just to be sure, check your placard.

The placard, among many things, tells the original tire size and the proper inflation pressure for that size.  The placard is usually located on a doorpost or in the glove box.

But as far as your wife's comments - well, this is a truck.  I'm not sure what may be meant by the comparison to a boat.  If she means it is vague in its direction, then higher inflation pressures will help.  If she means it's a bit choppy, it's a heavy duty truck and its going to do that.  

But for heaven's sake, don't be tempted to use something other than the inflation pressure on the placard unless you do the research needed to do this properly.  That means weighing the truck and performing the calculations to get the answer that's on the placard, so you understand what Ford did.  This is not something that should be taken lightly as overloaded tires can and will fail and the results are not pretty.

Hope this helps.