How big is a 205 75 15 tire?
The 205/75-15 Tire and Wheel Combo, # AM32395, is 8. An F78-14 tire and wheel will be about the same width but it will be 1 inch shorter. The difference in tyres is that the side wall of the 265/70R17 is 13. Given that there’s side wall on the top and bottom of the wheel it’s 26.
What size rim for 205 75R15?
For a 205/75-15, the best option would be a 5 inch rim. The reason that narrower is better is because it provides more support for the tire. Since trailer tires handle more vertical load, the narrow wheel that offers more support is ideal. That 20 mm difference affects how much rubber touches the road: A wider tire (225) usually gives you more grip and better cornering stability. A narrower tire (205) typically rolls more easily, which can boost fuel efficiency and deliver a slightly softer ride.