Tire Width...Using a 215 vice a 235.....pros?....cons?

sorry I am confused. From tire rack:

"Section Width
Following the letter(s) that identify the type of vehicle and/or type of service for which the tire was designed, the three-digit numeric portion identifies the tire's "Section Width" (cross section) in millimeters.

P225/50R16 91S

The 225 indicates this tire is 225 millimeters across from the widest point of its outer sidewall to the widest point of its inner sidewall when mounted and measured on a specified width wheel. This measurement is also referred to as the tire's section width. Because many people think of measurements in inches, the 225mm can be converted to inches by dividing the section width in millimeters by 25.4 (the number of millimeters per inch).

225mm / 25.4 = 8.86""

So seems to me the 235 and 215 respectively are indeed the tire's width (in mm)....am I mising something....

oh, so here are all the numbers....

My two options are:

235/85 R16

or

215/75 r16

The 215/75 r16 save me about $200

P.S. the stock trailer comes wityh 15 inch wheels. I have the option for 16 inch wheels.

Everything else being equal, 215s will be shorter and narrower. What size came on the trailer?

Mark

Those numbers are not the tires width, but rather the height. What are the rest of the numbers?