8 – 9 – 10 – 12 – Inch Trailer Tire Sizing Older Size Tire Size Overall Diameter 16.5 x 6.5 – 8 165/65-8 16.5 inches 18.5 x 8.5 – 8 215/60-8 18.3 inches – 6.90/6.00-9 21.1 inches – 205/50-10 18.3 inches Click to see full answer. Also know, what size are trailer tires?Trailer tire sizes are broken into main groups 12 inch and smaller and 13 inch and larger. Sizes 12 inch and smaller are generally listed by a two number size, such as 4.80-8 or 5.70-12. The first number in this size is the width of the tread, the second number is the size of the rim that it mounts on.Similarly, what size are trailer wheels? Standard sizes include 4-bolt on 4″, 5-bolt on 4.5″, 6-bolt on 5.5″, and 8-bolt on 6.5″. If you’re unsure about your 5-bolt pattern, we’ve put together a simple ‘bolt pattern template’ that makes it easy to ensure you purchase the correct trailer wheel for your trailer. Accordingly, can I put bigger tires on my utility trailer? You can add larger wheels and tires to a trailer as long as you have enough room for the larger size. Larger tires will typically have a higher weight rating. Tires with a higher weight rating will not increase the load carrying capacity of the trailer, so you will still be limited to the weight capacity of the axle.What does the D stand for on a trailer tire?The D is the designation for the internal construction of the tire. The D stands for diagonal or bias ply construction. That means the tire body plies inside the tire will crisscross. The 15 is the wheel diameter in inches and the C after the tire size will designate the load range.