this might sound real stupid but i was talking to my brother about tire sizes. what does the first number tell you and what does the second number tell you. we both agreed on the last number. is the first number the width. which number will make your truck higher. Thanks

 

the first number is the width of the tire in millimeters if you have a P-metric tire. e.g. P265R70 17. the second number after the width is the ratio of the sidewall width to the width. so in the previous example, the sidewall is 70% in height compared to the width. and of course, the last number is the diameter in inches for your rim. you would raise the circumference, and therefore the height, of your truck by going to a wider tire (which would also raise the sidewall height) and/or going to a higher profile tire (a lower "second" number). this would give you a taller sidewall as well. be advised that either would course of action would throw off your speedometer and odometer. you may also run into limits with your stock wheels. some on this board may be able to tell you about "31s" and "33s". bottom line, any bigger circumference affects the speedo.

 

275/60/17
1. take the first number 275 x .0394 = width (10.835")

2. take that number x (.)second number x 2 = total side wall height
10.835 x .60 = 6.501 (per side wall) x 2 = 13"

3. now take that number + the third number =30" tall tire
13" + 17"
so the tire is 10.835 wide x 30" tall

the first time i got custom tires and rims i was very unhappy with the outcome then i found this formula and instead of going in and asking for advice (everyone has a differnt idea of what looks good) i tell them what i want.

 

thanks guys this really helps me out. so you guys think some bfg's 285/75/16 would look cool on my 97 f150 supercab or something different