2 Cool Fishing Forum banner
1 - 20 of 21 Posts

· Roll Tide!
Joined
·
15,926 Posts
Discussion Starter · #1 ·
I need someone to explain truck tire sizing to me. I can't seem to get it from looking on the internet.

I need to replace some LT275/70/R18's on my F350. I would like to get something a bit wider, but do not want to change the overall diameter of the tire. What sizes should I be looking at?

Also, does anyone have any suggestions? I want an AT tire that gives a good balance grip in mud and sand but is still quiet and smooth on the highway.
 

· Registered
Joined
·
25,524 Posts
first number is the tread width - with more tread on the road, expect to loose a bit of fuel efficiency

Dueler AT Revo's are good tires. Keep them rotated regularly, as cupping was a problem when I bought a set several years ago on my last truck.
 

· Boatright custom flats
Joined
·
3,752 Posts
275 = WIDTH

70 = SIDEWALL HEIGHT

18 = WHEEL DIAMETER

If you've got a 275/70/18 and want to go wider, you'll need to look for like a 285 or possibly a 315. But remember this, the sidewall height is in direct relation to the width. For example, the 70 (correct me if I'm wrong), is 70% of the tire's WIDTH. So, a 315/70 is going to have a taller sidewall than a 275/70. Have I totally confused you yet?????
 

· Boatright custom flats
Joined
·
3,752 Posts
Like I said above, the 70 describes the sidewall height as a percentage. A 285/70 tire's sidewall, is 70% as tall as the TREAD is wide. A 315/70's sidewall is 70% as tall as the TREAD is wide. Same percentage, but wider tire equals taller sidewall.
 

· Boatright custom flats
Joined
·
3,752 Posts
To make it even clearer, look at a low profile tire, like a 225/40/15. The 40 has an extremely low profile sidewall. A 225/75/15 would have a very tall sidewall, resulting in a taller tire.

I agree w/Speckle on the brand. I had a set of Dueler Revo's on a Z71. I did a bunch of research before I bought them, and they had the best reviews for on and off-road performance. Bought mine at Firestone. They WILL match prices if you find them cheaper on the net too!
 

· Roll Tide!
Joined
·
15,926 Posts
Discussion Starter · #13 ·
Thanks for clearing this up for me guys! :spineyes: I think I'll just go buy a Civic!

Yes I do have a KR and have finally worn out those **** Conti's that came on it. I was hoping to get something decent to put on it without buying new rims or raising the ride height. It goes in the parking garage at work with 1" to spare and I don't want to park at the surface lot two blocks away.

LAt22, what is the diamter of those Toyos compared to the Conti's?
 

· Registered
Joined
·
101 Posts
tires

As to which tire to pick I would not go with the Nitto Terra Grapple;r poor mileage and I have been stuck in sand and mud both due to poor tread! I think the best all-terrain tire that I have used and witnessed is the B. F. Goodrich All Terrain! The Mud terrain they make is also exceptional off-road and very mild mannered on-road; with a very good tread life! But its all buyer opinion!

Chad
 

· Registered
Joined
·
199 Posts
Tire size

The exact way to convert
275 width in milimeters 275/25.4 = 10.82 width in inches
70 percent of the width that the side wall of the tire is equal to (distance from the edge of the rim to the tread) 257*.70 = 192.5mm or 7.58 inches
Now to determine the total hight of the tire you add the side wall hight (twice because from the ground up you have rubber rim rubber) plus the rim height 7.58+7.58+18 = 33.16

So the size of your tires are 33.16 tall and 10.82 wide. When you chane only the first number both sizes change because the second is a percentage of the first.

To make it worse some companies measure a little on the bigger side while some measure a little on the smaller side. Also a block tread will always looke wider than a rounded tread.

As to what you should run a your SD. Nitto Terra Grappler and Toyo Open Country ALL TA are almost identical. Both make a good number of tires in 18, and most (unlike other companies) are load range E. A 325 60 18 will clear stock and be quite a bit wider but not any taller, a 325 65 18 will be a littler taller and wider than stock, but without a replacement bumper you will need a leveling kit. BFG has recently come out with some additionas to the 18 inch rim market, but I am not surer the exact sizes. I think they have some in between the sock and the Nitto/Toyo like a 285 60 18, 285 65 18, 305 65 18 and a 35 12.50 18 in the All TA tread.

I run 35 12.50 18 BFG muds on my SD, and would like to switch to 35 12.50 18 Toyo MTs but dont want to pay what they cost. If I was going to run an all terain I would run the 325 65 18 Nittos, they are easier to find then the Toyos and a little cheaper. I do however have a leveling kit.

Hope this helps.
 
1 - 20 of 21 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top