BioJoe

You must have missed what I said. The first number is the WIDTH of the tire in mm. It DOES NOT MATTER UNLESS you use the SECOND (and third if you are changing rim sizes) number to calculate. The reason the 285/75 is taller than the 265/75 is because of the SECOND number. 75 percent of 285 is MORE than 75 percent of 265. You can't ask for a tire by only using one number. Call a tire shop and ask them how much are 285's and don't give them anymore information and see what they tell you.

BioJoe

There is no such thing as a "standard tire size". "We" don't know what they are saying because they aren't telling us the rest of the information. Tire sizes are gives as width, sidewall ratio, rim size, and sometimes a letter telling you what it's made for like a speed rating and then maybe a MS for mud/snow etc. You can't buy a tire using only one number. That's why you shouldn't talk about tires unless you use all the numbers. When the first poster asked about what size his tire needed to be to change final drive ratio he needs to know how tall his tires will be overall. The ONLY way to know that is to have the tire size which is all the numbers or in the case of off road tires the tire height number.

AH64ID

Sorry, but they are standard tire sizes.... With a width we just about all know what 99.9% of people are talking about.... Yes you need the width, aspect ratio, and rim size to calculate the actual size (which actually is only an approximate size as many metric tires converted to flotation size aren't 100% accurate)...

A 285 is a 33x11.50.. whether is a 285/70/17 or 285/75/16....