I had to order a replacement wheel for my popup as explained in another post. This forced me to start thinking about my tire sizes and load ranges. My 2006 Fleetwood Santa Fe was bought used. The tires on the ground are 185 x 13 with a load range of D on aluminum wheels. The spare is on a different style, white steal wheel and with a 175 x 13 load range C. The 2006 parts catalog lists a mag tire/wheel and a spare tire/wheel, both with "Id D" but with no size designation other than 13 inch. I take the D to mean the construction of the tire and not the load range because when they list the tire only later, they use "LR D" which I take as load range D. So, did Fleetwood intend for me to use the Load Range C spare if one of the heavier tires failed? That does not compute.