Cooper Discoverer atr

[804xluv]

Is anyone running these? I'm bout a month from a new set of tires. I'm going with 315/75/16's. I like the look of the Hankook RF10 and the Cooper Discoverer ATR. Opinions on both would be greatly appreciated. Thanks

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1994 reg cab long bed, auto, 4x4. 310,000 miles, straight pipe, everything else stock for now.

[804xluv]

anyone????

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1994 reg cab long bed, auto, 4x4. 310,000 miles, straight pipe, everything else stock for now.

[mjd91]

I had some cooper discoverers on my truck. Towards the end of their life (not worn out) they threw about half the tread off the driver side steer tire though. So I got BFG's now.

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2000 short, 4x4, 6 speed, 12.25" DD Valair, S.O.VP44, AEM Brute Force HD, FBD 5" with 6" tip, ADRENALINE!!!, AirDog II 165, AutoMeter Cobalts, 35" Mud Grapplers on 18" Black XD Diesels

[Fisherguy]

Originally Posted by 804xluv

Is anyone running these? I'm bout a month from a new set of tires. I'm going with 315/75/16's. I like the look of the Hankook RF10 and the Cooper Discoverer ATR. Opinions on both would be greatly appreciated. Thanks

I wouldn't get either one, especially if you carry any kinda weght, they're only D rated.
I had 2 flats last year with my D rated 285 ATR's going 70mph, loaded towing my trailer. Both times by the time I pulled over and took the tires to get repaired I was told the sidewalls were shot. I like the ATR's, but they're not ballsy enough IMO.

I just put on some 35" E rated Vortracs.
Deffinately stay away from 315 BFG AT's.

__________________
06 QC 3500, Raider cap; custom rack; DiPric gauges; 40" Nelson; S&B intake; BDTD CL; Quad X2: Pac Brake PRXB/air bags with Airlift Wireless; AD 100/Liberty canister; 4 KC's, Randy Ellis light bar; SB OFE, leveled, Bilsteins, 35" Vortracs/H2's; ATS Flares

[Haywood_U]

Originally Posted by Fisherguy

I wouldn't get either one, especially if you carry any kinda weght, they're only D rated.
I had 2 flats last year with my D rated 285 ATR's going 70mph, loaded towing my trailer. Both times by the time I pulled over and took the tires to get repaired I was told the sidewalls were shot. I like the ATR's, but they're not ballsy enough IMO.

I just put on some 35" E rated Vortracs.
Deffinately stay away from 315 BFG AT's.

I don't know that there is a major difference in D and E rated tires - as far as weight is concerned.

The load range only dictates the sidewall strength and amount of air the tires can hold. D rated (8 ply) can only take up to 65 psi, while E rated (10 ply) can take up to 80 psi.

I think when you get into weight, you have to start looking at the load index of the particular tires.

Tire Tech Information - Load Range/Ply Rating Identification


Load Index Chart - Discount Tire



Load Range, Ply - Speed Rating & Load Index



It may be that "E" tires may tend to have a higher index than "D" tires, but I don't know that is an established rule. I believe when I was looking the difference was 100lbs between the E and D tires I was looking at.

Just looking at tirerack, they had both E and D rated tires in the OPs mentioned size. I looked at 1 from each and they both had a 121 load index.

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2001 Ram 2500, Quad cab SB, 4x4.

[Fisherguy]

I guarantee neither the Cooper or Hankook comes in an E rated 315-16.
There's more than a 100 pound difference between a D and E rated tire in a given size and not all E's are rated at 80 psi, not all D rated are good for 65 either, depends on the size of the tire.

Cooper Tires - Tire Specifications

The sidewall was my issue with the ATR's.

__________________
06 QC 3500, Raider cap; custom rack; DiPric gauges; 40" Nelson; S&B intake; BDTD CL; Quad X2: Pac Brake PRXB/air bags with Airlift Wireless; AD 100/Liberty canister; 4 KC's, Randy Ellis light bar; SB OFE, leveled, Bilsteins, 35" Vortracs/H2's; ATS Flares

[804xluv]

I don't haul a lot of weight. I put a lot of miles on for work. right now I'm at about 80 miles round trip. I need a tire that is gonna hold up for at least 40k, hopefully more. I also need a tough tire with decent tread. I work on a bridge crew and sometimes they will just see pavement but a lot of the time there is a lot of mud and other terrain. Thanks for the input

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1994 reg cab long bed, auto, 4x4. 310,000 miles, straight pipe, everything else stock for now.

[Haywood_U]

Originally Posted by Fisherguy

I guarantee neither the Cooper or Hankook comes in an E rated 315-16.
There's more than a 100 pound difference between a D and E rated tire in a given size and not all E's are rated at 80 psi, not all D rated are good for 65 either, depends on the size of the tire.

Cooper Tires - Tire Specifications

The sidewall was my issue with the ATR's.

In my limited experience, there aren't a whole lot of E-rated times in larger sizes.

The 100 lb difference was given as a true number - I don't remember what the actual difference was between the 2 tires I was looking it, but it wasn't a large enough difference to make me shy away from the D-rated tire.

I had 2 choices - 245/75/16 or 265/75/16 - when you buy from a retail shop they will only sell you what the book says should go on your vehicle.

The 245 was available in E-rating, and the 265 was a D-rated tire. Again, I don't remember the exact numbers, but I believe there was only a difference in the load index by 2. I want to say it was 120 vs 122 (or 119 vs 121).

That's a difference of 199-221 lbs per tire. I don't do much hauling or towing, so it wasn't a concern for me.

As far as I understand the load rating, ply and sidewall info, it only had to with the strength of the sidewall and amount of air pressure. I'm not aware that the PSI changes based on tire size. I can only find charts that say that D are rated at 8 ply and rated for 65 psi. E-ratings are 10 ply and 80 psi.

Same with load index. I can't find anything that tells me that the load index varies with tire size. A load index of 121 (3197 lbs) is the same whether the tire is 315/75/16 or 245/75/16.

Same with speed rating. A speed rating of R is rated up to 106 mph regardless of the tire size.

I'm in no way a tire expert. I can only provide links to back up that information. If those numbers are incorrect
then I apologize. I'm new to the diesel and large truck scene, so when I needed new tires I spent several hours doing research before buying. The last thing I wanted to do was risk damaging my new truck by putting on the wrong tires - and I had people insisting that I HAD to put on an E-rated tire because I had a 2500 Heavy Duty Diesel.


Load index ratings.

Load range/ply info.


As far the size mentioned by the OP, tirerack lists 17 tires available. Of those 17:

12 are D rated, with 11 having a load index of 121 (3197 lbs), and 1 not having a load index listed;
1 is C rated, with a load index of 113 (2535 lbs);
4 are E rated, with 3 having a load index of 127 (3858 lbs), and 1 having a load index of 121 (3197 lbs).


Compare Tire Search Results


Compare Tire Search Results

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2001 Ram 2500, Quad cab SB, 4x4.

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Last edited by Haywood_U : 04-23-2009 at 12:11 PM.

[strai8up]

go with the nitto terra grapler

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2005 SLT 2500 Hypertech max energy,southbend clutch ofe, b&w turnover ball

[Harley27]

I have Cooper ATR 315 70 -17 They ride ok, but don't balance for crap. Roughly 5 ounces per tire. After only 1000 miles I show no wear so I cant say how long they last.

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2006 Ram 2500 QC SB 6 Speed 4X4
Smarty, High Ram intake, Silverline turbo back, AEM Workhorse, Auto Meter Fuel, Boost, EGT, South Bend DD, Fluidamper, Kore HP. Airdog 150.

[Fisherguy]

Originally Posted by Haywood_U

In my limited experience, there aren't a whole lot of E-rated times in larger sizes.

.....

.....


.....


As far the size mentioned by the OP, tirerack lists 17 tires available. Of those 17:

12 are D rated, with 11 having a load index of 121 (3197 lbs), and 1 not having a load index listed;
1 is C rated, with a load index of 113 (2535 lbs);
4 are E rated, with 3 having a load index of 127 (3858 lbs), and 1 having a load index of 121 (3197 lbs).

Yes it is hard to find big tires that are E rated, my 35" Vortracs are. I still think no matter what size you get for our trucks an E would be better than a D.

Of those 17 you list, none of them are E rated in the size 315/75/16 he's looking for, you said above both the Coopers and Hankooks are.

__________________
06 QC 3500, Raider cap; custom rack; DiPric gauges; 40" Nelson; S&B intake; BDTD CL; Quad X2: Pac Brake PRXB/air bags with Airlift Wireless; AD 100/Liberty canister; 4 KC's, Randy Ellis light bar; SB OFE, leveled, Bilsteins, 35" Vortracs/H2's; ATS Flares

[Haywood_U]

Originally Posted by Fisherguy

Yes it is hard to find big tires that are E rated, my 35" Vortracs are. I still think no matter what size you get for our trucks an E would be better than a D.

Of those 17 you list, none of them are E rated in the size 315/75/16 he's looking for, you said above both the Coopers and Hankooks are.

I agree that if an E is available it would be better than a D. Just trying to point out that he shouldn't avoid a D-rated tire just because it isn't an E-rated tire. A D-rated tire may be enough for his desired uses.

If he has the need for an E-rated tire then he should definitely get one. Personally, I don't haul or tow much, so the difference to me didn't play a major factor in my decision.


I never looked at the tires that were mentioned in the OP. I just said that E-rated tires were available in that size - 315/75/16.

The four E-rated tires in that size from tirerack are:

Goodyear Wrangler DuraTrac

Dick Cepek Crusher

Dunlop Rover M/T Maxx Traction

Kumho Road Venture MT KL71





Of course, I just realized I've gone completely off-topic. I have no experience with those 2 tires. I run a store branded Cooper made A/T tire (Pep Boys Dakota A/T)......in a much smaller size. I haven't had any problems with the tires, but again they aren't the two that were specifically mentioned in the OP.


804xluv - if you have a Pep Boys near you, you might want to look at the Dakota A/Ts. They are made by Cooper and look similar to the Cooper branded tire they carry (I believe it was the Discoverer ATR). I don't have my paperwork with me, but I believe the Dakota's have a 50k tread wear warranty. I believe the price difference was around $25/tire less than the Coopers.

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2001 Ram 2500, Quad cab SB, 4x4.