ste6168

How do you all figure out the height of tires...? I have been a car person my whole life and never really understood how truck tires get measured in 30" 31" 33" 35" etc. How do you figure out the height of the tires (without measuring them) just by the normal numbers (ex: 285x65x17, <made up on the spot, might not even be a real tire size).

Also, when I get my truck and need new tires I want to level it and put some 33's on it. If I wanted to use the stock wheels (17"s), what size tires would I need to buy in order for them to be 33's. Or would I be better off buying larger wheels, like 18"s-20"s?

Main question though, how do you figure out the height of the tires? I searched google for a tire height calculator, and came up short... Thanks

boilerup15

this website has the OD our outside diameter of the tire next to the metric sizes. Hope it helps. Also found this website to be one of the cheapest on tires. http://www.rimzoneonline.com/nittoterragrappler.htm#17

ste6168

Ok thanks, That works for the tires there, but is there an easy way to find out for EVERY tire. For one reason or another, what if I wanted to find out the OD of the tires on my parents SUV?

driver444

Take For example...

285-75-17

The 285 means 285 millimeters, and refers to the width of the tire.
The 75 is the aspect ratio, and means that the sidewall height of the tire is 75% of the tread width. The 17 is obviously the rim size.

Most tire manufacturers will show the specs and Actual tire size on their websites. A good size tire for the 17 inch rim is a 265-70-17 or 285-70-17. I believe those tires are 32.8 inches or so.

Hazjeff

I recommend to check the manufacturers web site for the tire specs, including the recommended rim width. I wanted to stick with stock rims but the tires I wanted required a wider rim.

ste6168

Well, I don't know what happened with my google search earlier (must have typed something different), but I just re-did the search and found a great site. Figured I would post it to this thread for others to use as it will definitely help me when deciding what tire size to go with! Thanks, and sorry for the troubles, found what I was looking for anyway

Link: http://www.1010tires.com/tiresizecalculator.asp

ford4wd08

here is a nother great website i found the other night when i was wondering the same question, precitae it google ha

http://www.redrock4x4.com/tech/tire_calc.php

ste6168

OK. I have an additional question to my original. I searched and couldn't find much. If I run the stock 17's, would a P265/65R17 tire run ok? If so that would be great as I have an endless supply of that size tire. (none of them will be new, but I could change tires every 5000 miles if need be.

Jaslar12002

yes it would be slightly widder than the 255 and about the sam hieght since you are reducing the sidewall ratio

beetlebz

to figure them out on your own... (get out your pen and paper :P )

my gen grabber AT2s are 275/65R18. like was already said (well said driver444!), R is your rim diameter... mine are 18" stock FX4 rims (god i love em). to calculate...

driver444 taught us that the first number is the width... the 275, and the second number is the aspect ratio. So... mine are a 65% aspect ratio. 65% of 275mm (275*0.65) is 178.75mm. Thats how thick the sidewall of the tire is from the outside diameter to the rim. Double that number (because the height of the tire has both sidewalls!) (178.75*2), thats 357.5 millimeters, or 35.75 (357.5/10) centimeters. We learned in school that 2.54 centimeters equals 1 inch, so divide 35.75 by 2.54 (35.75/2.54) that gives us 14.07 inches of rubber from the top of the tire, to the bottom.

we already know thanks to driver444 that the R18 is the size of my rim, so if youre looking at the rim from the side youre going to see 18" of rim, and 14.07 inches of rubber. giving us a grand total of 32.07"

sooo I have a 32" tire.

hope that helps!