Ah, the good old days ... when a 30x9.50 was roughly that, about 30" tall by 9-1/2" wide no matter what size rim it was monted on. Then we went "global" and tire sizes in the P/LT-metric world get a bit tricky.
As mentioned earlier, a 225/75-16 is about 1" taller than a 225/70-16, as only the aspect ratio number changed. But a 235/70-16, though wider than the 225/75 by almost 1/2", is only 1/4" smaller in diameter. This is due to the way the whole Sizing Scale is set up.
You can find a better, more detailed description on some of the tire sites, but here is the whole thing in a Reader's Digest version. (I hope I don't get confussed and mess this up... and please correct me if I'm wrong)
225/75-16
- You start with a tire width, "225mm" in this case.
- The height - of the sidewall - is a pecentage of the width. 75% in this case, or (225x0.75) 168.75mm.
- The total height of the tire is 168.75x2 (2 sidewal heights) + rim diameter.
Thats right a 225/75-16 is an inch shorter than a 225/75-17 Even though the width and aspect ratio numbers are the same!
As I have no real background in the metric system, or tire sizing, when I went looking for some new shoes for my Libby, I made up a spreadsheet that translated the metric sizing into good ol' inches. It also allowed me to enter several different sizes on different lines and compare width, diameter, and sidewall heights in a familar format.
In short, with the factory "Blvd Crusier Chrome" 17 inch rims on my 2006 4x4 Limited, I ended up replacing the tires with Toyo "Open Country" ATs of the same size 235/65-17. Don't get me wrong - they have been GREAT TIRES! But, they where about the only ATs I was able to find in that size.
In Fact, I liked the Open Contry's so much, I put them on my full size Ram. And BTW, the set of 4 265/75-16s for the truck were $100usd less
Can't wait to get the liby lifted, and some 16'inch rims - all it takes is money...
Anyone know of a bank giving out "samples"!
UK
