All tires have a design wheel width.  Other widths are allowable within a range.  The sidewalls are designed to have a mild "S" shape with buttresses in the bead and where the sidewall meets the tread to provide the stiffness the engineer wanted for its application.  I chose 205 so the wheel width put the tire beads in the right position vs. the tread width, at least theoretically matching the design shape.  Plus, I didn't need to go wider to increase my F.S.  I hate to see sports cars with stretched sidewalls, besides goofy, it is not best for traction, or likely safety.  A Dunlop engineer told me the optimum rim for handling was 85 - 90% of a tires tread width.  The other side of that is a fat tire on a narrow rim.  There, the buttresses are so distorted they can't do their job. 

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I went with Carlysle ST205/75R-14 in Load Range D to get more load rating and higher speed rating.  I kept the OEM size on the OEM rims so the sidewalls kept the design curvature and had their expected stiffness.  there is not much detectable difference between the original tires and the Carlysles while towing, but I have greater margins on load and speed that makes me feel better. 

the Goodyears are "D" range tires. and have adequate speed and weight ratings

most trailer tires are not automatically balanced unless the buyer specifies them to be balanced

Vann

Last week I purchased a set of Carlisle Radial Trail "D" 205/75/14, 8 ply tires and noticed a huge difference from my last set of Hartland "C" 205/75/14.  This was due to strong crosswinds, 30+ mph and even though I tow with a pickup I could see the sidewalls on the Hartlands flex when the winds were severe, even to the point that I could feel the back of the pickup want to move a bit a well.  I do utilize a Curt anti sway bar (friction bar).  On the return trip (35 miles) the winds were as strong if not stronger and there was no flexing noted on the Carlisle sidewalls, resulting in a much smoother ride inside the TV as well.  This is now my third set of tires and the first time going with a "D" rated tire, what a difference, I am sold on it!

Make sure you let the tire person know you want your wheels balanced, they won't do it unless you ask, at least where I purchased mine (Discount Tire) that is the case.

we installed Goodyear Endurance 215/r75/14and are very happy with them.  they don't leak, tow smooth and seem very hardy.Whatever tires you buy, make sure they are balanced properly.

Vann