first off Ive got stock 275/60s on a 17 in. rim. My bro has 265/70s on a 16in. rim on his 06 tacoma. Im going to get 265/70s on my f150 before long and was wondering: Would my tire be bigger/taller than his? where exactly does the 60-70 number come from? is that from the middle of the wheel or off the top of the rim?

He has the prerunner v6 SR5 and Lookin at it once I get tires and my level in mine will be taller than his.

in the taller size, will the 0ff-road tire be taller than a all on-road tire?

 

Some who probably know better than I can answer, but my understanding is that 60 or 70 is an aspect ratio of the tire. On the cross section of the tire, it is the tire width with respect to the tire height. The smaller the #, the more profile you get. Example, my 20in tire is a 55, where the 18 in tire to be the same overall diameter equevalant would need to be a 65 to 70 range.

Example 275-55R20 is roughly equal to 275-65R18

Go ahead, shoot holes in this

 

275/60-17 = 29.99 in = you now
265/70-16 = 30.60 in = him now
265/70-17 = 31.60 in = you in the future


http://www.1010tires.com/TireSizeCalculator.asp

 

it comes up with the warning about staying within 3% of the diameter of the original tire or ill face brake trouble.....solutions?

 

That's misinformation. There are members here running huge tires with no problems with brakes. Obviously, when you go with a much taller or heavier tire you are gonna decrease braking performance accordingly, but it's not like you are installing 44's.

 

thats exactly what I thought. If I could id like to get a big brake kit but i think the ones I have now fill all the space unless i get bigger rims.


but would a off-road tire vs a street tire in the same size (265/70) be "taller" or would they sit the exact same height?

 

For future reference, I posted this a while back, it may help you out.
https://www.f150online.com/forums/wh...tire-size.html

 

ok i got the tire size. but if i have a 265/70 hardcore off roading tire and a 265/70 perf. street tire will the both be the same height?

 

I think that goes to the manufacturer, your best bet is to pull up the tire specs chart and look at the overall diameter value. Very often from one company to the other, reguardless of tire type size varies for examples:

BFG LongTrail T/A "Street" (265/70/17) = 31.7"
Pirelli Scorpion ATR (265/70/17) = 31.6"
BFG AT (265/70/17) = 31.8"
Fireston Destination AT (265/70/17) = 31.9"
BFG MT (265/70/17) = 31.9"

With this being said street vs at vs mt is not going to change a whole lot, like I said just go look up exact specs for the tires your interested in. Hope this helps.