Tire sizing Question! In a pinch! (tires, axle, used, work)

[Diana Holbrook]

Nevermind! Found answer!

[rstevens62]

Originally Posted by Diana Holbrook

I don't understand tire sizing.
Can a 205/75D15 trailer tire be used as a spare along with ST225/75R15 tires on a horse trailer?
Dual axle trailer of course.

Yes it will fit.


The first 3 numbers refer to width of the tire,(in mm), the next 2 numbers are aspect ratio,(sidewall height, from the tip of the wheel to the top of the tire). The R stands for radial tire, Im not sure what the D stands for, but the size is very similar. a 225 tire would be a little bit wider than a 205, but only by 15mm. they with both work fine on the same rim/wheel.


The 15 refers to the wheel size (dia.)

[AlaskaErik]

Originally Posted by rstevens62

Yes it will fit.


The first 3 numbers refer to width of the tire,(in mm), the next 2 numbers are aspect ratio,(sidewall height, from the tip of the wheel to the top of the tire). The R stands for radial tire, Im not sure what the D stands for, but the size is very similar. a 225 tire would be a little bit wider than a 205, but only by 15mm. they with both work fine on the same rim/wheel.


The 15 refers to the wheel size (dia.)

225 minus 205 = 20. So a 225 mm wide tire would be 20 mm wider than a 205 mm wide tire.

[Diana Holbrook]

Thanks guys!

They might have fit.... but we found out friend's trailer has six bolts and my spare only has 5.

So... couldn't help.


That part we couldn't make work.