What does tire load range and / or load index mean?

Moab

TJ Expert
Supporting Member
Joined
Dec 15, 2018
Messages
3,162
Location
El Segundo, California
I'm completely confused by different companies use of a letter or number to express "tire load range". Or is it "tire load index"? I'm completely confused. Some companies use letters - others use numbers. Or so it seems. I've tried searching google. To no avail. Is there a chart someplace that reconciles these?

I'm trying to figure out if these load index 115 tires are C or D rated?

https://www.walmart.com/ip/Falken-Wildpeak-AT3W-265-70R17-Tire/54383695
 
They are "Passenger" rated tires (4 ply)

They might be what is considered "extra load handling" but they are not traditional 6, 8, or 10 ply "Light Truck" rated tire
 
  • Like
Reactions: Head Lice
If it were a 6 ply or above it would be labeled with an LT before or after the sizing numbers

eg; LT 265/70R17
 
  • Like
Reactions: Chris
Any tire you get for your TJ should be a light truck tire. Eg: LT 265/75R16. A car tire is labeled with a "P"
Eg: P265/75R16.
 
I'm completely confused by different companies use of a letter or number to express "tire load range". Or is it "tire load index"? I'm completely confused. Some companies use letters - others use numbers. Or so it seems. I've tried searching google. To no avail. Is there a chart someplace that reconciles these?

I'm trying to figure out if these load index 115 tires are C or D rated?

https://www.walmart.com/ip/Falken-Wildpeak-AT3W-265-70R17-Tire/54383695
Just out of curiosity, what is your intended use for the vehicle you are looking at these tires for? If you don't plan on going off road then the tires you linked are more than adequate, for any Jeep vehicle. Jeep themselves only puts 6 ply rated tires on specific models like the Rubicon and some other "packaged" editions.
 
  • Like
Reactions: Blondie70
Just out of curiosity, what is your intended use for the vehicle you are looking at these tires for? If you don't plan on going off road then the tires you linked are more than adequate, for any Jeep vehicle. Jeep themselves only puts 6 ply rated tires on specific models like the Rubicon and some other "packaged" editions.

Street and old logging roads is about it. I live in LA right now. But will be moving home to WA in the next one to two years.

I'm mostly concerned about the letter load rating of the tire. And that it's a "C". I'm looking for new tires. But most are "E" or above. I would prefer an LT tire. In something that is more aggressive looking. Short of an M/T tire. If that makes sense. LT265/70r17 C rated.

I perused the posted links above. But still can't find a simple chart that matches the number ratings with the letter ratings. Some companies use letters (which are much easier to understand and compare tires with.) others use numbers. So it's hard to tell which tires are "C" rated. I'm to tired and busy this weekend to research it further. This is as far as I have gotten. Not in a rush though.

First I started with Patagonia M/T's which are made of a soft rubber so they are not so loud on the pavement. But they are E rated in my size. So those were out.

Then I found some BFG Rugged Terrain. https://www.walmart.com/ip/BFGoodrich-Rugged-Terrain-T-A-Tire-P265-70R17-113T/764086496 But they seem more like a street tire. (As you can tell I'm looking for a good deal. I don't have more than about $115 a tire to spend.)

Cooper offers this. https://www.walmart.com/ip/Cooper-DISCOVERER-A-T-265-70R17-115T-Tire-60-000/392022338 But again looks like a street tire to me.

Then these Falkans. But they appear to not be C rated. And I don't want a harsh ride.

I've even been looking at used BFG KO2's and Duratracs. As well as a few others Nitto etc. But really reluctant. There's a huge selection here in LA of used tires. As you can imagine. I'd buy some take offs. With a few miles on them. If I could find 5 of them with limited wear and within my budget. So far I've only found trashed tires or guys that think they are made of gold.

I found one guy with a set of BFG KO2 Baja Editions and rims off a JK. https://losangeles.craigslist.org/lgb/wto/d/whittier-wheels-and-tires-off-2017-jeep/7030600514.html But he wants a grand for them. And I don't need rims. But those Baja Edition KO2's look awesome. Wish I could afford a new pair. And it's not likely I will. The $115 cap is set by my wife. As we have alot more pressing items to look into and purchase. Plus a kid in college that needs a car.

I think I'll keep looking for a set of take offs from a JK. Or any other truck or suv with a similar tire. At least on K02's the load rating is clearly marked by a C, D or what have you.
 
Street and old logging roads is about it. I live in LA right now. But will be moving home to WA in the next one to two years.

I'm mostly concerned about the letter load rating of the tire. And that it's a "C". I'm looking for new tires. But most are "E" or above. I would prefer an LT tire. In something that is more aggressive looking. Short of an M/T tire. If that makes sense. LT265/70r17 C rated.

I perused the posted links above. But still can't find a simple chart that matches the number ratings with the letter ratings. Some companies use letters (which are much easier to understand and compare tires with.) others use numbers. So it's hard to tell which tires are "C" rated. I'm to tired and busy this weekend to research it further. This is as far as I have gotten. Not in a rush though.

First I started with Patagonia M/T's which are made of a soft rubber so they are not so loud on the pavement. But they are E rated in my size. So those were out.

Then I found some BFG Rugged Terrain. https://www.walmart.com/ip/BFGoodrich-Rugged-Terrain-T-A-Tire-P265-70R17-113T/764086496 But they seem more like a street tire. (As you can tell I'm looking for a good deal. I don't have more than about $115 a tire to spend.)

Cooper offers this. https://www.walmart.com/ip/Cooper-DISCOVERER-A-T-265-70R17-115T-Tire-60-000/392022338 But again looks like a street tire to me.

Then these Falkans. But they appear to not be C rated. And I don't want a harsh ride.

I've even been looking at used BFG KO2's and Duratracs. As well as a few others Nitto etc. But really reluctant. There's a huge selection here in LA of used tires. As you can imagine. I'd buy some take offs. With a few miles on them. If I could find 5 of them with limited wear and within my budget. So far I've only found trashed tires or guys that think they are made of gold.

I found one guy with a set of BFG KO2 Baja Editions and rims off a JK. https://losangeles.craigslist.org/lgb/wto/d/whittier-wheels-and-tires-off-2017-jeep/7030600514.html But he wants a grand for them. And I don't need rims. But those Baja Edition KO2's look awesome. Wish I could afford a new pair. And it's not likely I will. The $115 cap is set by my wife. As we have alot more pressing items to look into and purchase. Plus a kid in college that needs a car.

I think I'll keep looking for a set of take offs from a JK. Or any other truck or suv with a similar tire. At least on K02's the load rating is clearly marked by a C, D or what have you.
Understandable on all accounts. As someone who has been in the tire industry I can tell you with nearly 100% certainty(I have been out of it for a few years now) Any tire that is NOT delineated with an LT as part of metric sizing is going to be a "4ply" or "Passenger" rated.

That being said the advantage of a 6 ply over a 4 ply for the purpose of off roading is a sturdier construction that is more forgiving and better equipt to handle what we as off road enthusiasts do... Airing down, dealing with sharp rocks or sticks, etc. For what you are wanting to do with your tires any of the ones you listed would safely fit that bill. The ones you listed in your opening post are a 4 ply rated tire and they are close to the same "load carrying capacity" of a 6 ply rated tire, and looks like they are specifically designed to be used on SUVs and half ton trucks.

IMHO I do not think you would have any issues running them even though they are not a 6 ply tire. I hope that helps as a general answer. I could get more into the specifics of you care to!
 
  • Like
Reactions: THunter
"I'm completely confused" ...
try this ...

https://en.wikipedia.org/wiki/Tire_code
If their intent was to simplify how "Flotation" sizing is demonstrated they did so miserably in this particular section.

3- or 4-digit number: The section width (cross-section) of the tire in inches. If the tire diameter is not given, section widths ending in zero (e.g., 7.00 or 10.50) indicate the aspect ratio of 92%, while section widths not ending in zero (e.g., 7.05 or 10.55) indicate the aspect ratio of 82%. These aspect ratios often vary from today's tire manufacturer specification.

That's some real Old School sizing information there... 🤣 🤣
 
Old skool is R85-15LT
Yep, Alpha numeric sizing.
I think Buckshot and Gumbo were some of the last tires to use that sizing style.
That would be the equivalent of a 37x9.50X15 bias ply tire in today's tires
37" diameter 9.3" tread width for a 15" rim,
R being the load rating = Truck or LT
85 being the aspect ratio 37x9.3
15 inch rim size
 
Yep, Alpha numeric sizing.
I think Buckshot and Gumbo were some of the last tires to use that sizing style.
That would be the equivalent of a 37x9.50X15 bias ply tire in today's tires
37" diameter 9.3" tread width for a 15" rim,
R being the load rating = Truck or LT
85 being the aspect ratio 37x9.3
15 inch rim size
Yep, the buckshots sound like a B-29 on take off power going down the highway. I still have one in the back yard that I bought in the early 90's.
 
  • Haha
Reactions: reddvltj
Back to the OP's original concern here's a reference for load index ratings

Load Rating
The load rating is often found after the size numbers in the tire size of passenger car tires. A P195/60R15 87S would have a load rating of 87.

Load Index (E.T.R.T.O. 1991 - Section 13)
Code
Pounds
Kilograms
Code
Pounds
Kilograms
Code
Pounds
Kilograms
Code
Pounds
Kilograms
60
551​
250​
80
992​
450​
100
1,764​
800​
120
3,087​
1,400​
61
567​
257​
81
1,019​
462​
101
1,819​
825​
121
3,197​
1,450​
62
584​
265​
82
1,047​
475​
102
1,874​
850​
122
3,306​
1,500​
63
600​
272​
83
1,074​
487​
103
1,929​
875​
123
3,418​
1,550​
64
617​
280​
84
1,102​
500​
104
1,984​
900​
124
3,528​
1,600​
65
640​
290​
85
1,135​
515​
105
2,039​
925​
125
3,638​
1,650​
66
661​
300​
86
1,168​
530​
106
2,094​
950​
67
677​
307​
87
1,201​
545​
107
2,149​
975​
68
695​
315​
88
1,235​
560​
108
2,205​
1,000​
69
717​
325​
89
1,279​
580​
109
2,271​
1,030​
70
738​
335​
90
1,323​
600​
110
2,337​
1,060​
71
761​
345​
91
1,356​
615​
111
2,403​
1,090​
72
783​
355​
92
1,389​
630​
112
2,470​
1,120​
73
805​
365​
93
1,433​
650​
113
2,536​
1,150​
74
827​
375​
94
1,477​
670​
114
2,601​
1,180​
75
853​
387​
95
1,521​
690​
115
2,679​
1,215​
76
882​
400​
96
1,565​
710​
116
2,756​
1,250​
77
908​
412​
97
1,609​
730​
117
2,833​
1,285​
78
937​
425​
98
1,653​
750​
118
2,910​
1,320​
79
963​
437​
99
1,709​
775​
119
2,999​
1,360​


Load Range
Load range is used on light truck tires and indicates ply rating and load pressure (PSI).

Load Range
Ply Rating
Load Pressure (PSI)
B
4​
35​
C
6​
50​
D
8​
65​
E
10​
80​
F
12​
95​