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Cooper Discoverer STT Pro 38X15.50R18 D/8PLY BSW

Truck/SUV - Mud Terrain
Mud Terrain

Free Installation — That’s up to $111.96 in savings when you buy 4 tires! | Only applicable by choosing one of our partner installers at checkout.

No coupon needed. Valid with 2,000+ partnered installers at checkout.

Rims Not Included

easy test score

9.8 Superb

Availability

In Stock

Per Tire:

$708.67

Lightning Savings

Was $885.84

$17.76

Estimated Delivery

Shipping Cost

Tire coverage

$705.84

Installation available

Total

DISCOUNTS & OFFERS

Free Road Hazard Protection |

Value:

Free Installation — That’s up to $111.96 in savings when you buy 4 tires! | Only applicable by choosing one of our partner installers at checkout.

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About the Manufacturer:

Founded in 1914 in the United States, Cooper Tires has built a century-long legacy as a cornerstone of the global replacement tire market. Now operating as a subsidiary of the Goodyear Tire & Rubber Company, the brand combines historic American engineering with cutting-edge global resources to deliver exceptional value and durability.

While Cooper boasts a rich motorsport heritage, most notably as the former long-time title partner of the Road to Indy development program, its primary focus today is strictly on consumer-driven innovation and advanced R&D.

Why Drivers Choose Cooper:

American Heritage & Expertise: Over 100 years of tire manufacturing experience, specializing in premium, high-quality aftermarket replacements.

Versatile Engineering: A comprehensive global lineup offering advanced safety, longevity, and rugged all-terrain capability.

Broad Vehicle Coverage: Reliable, budget-friendly performance engineered specifically for passenger cars, CUVs, SUVs, light trucks, and commercial vehicles.

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(855) 770-3279

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Specifications

Specs

Value

Description

Sidewall

BSW

Describes the sidewall appearance. Examples: BSW= Black Side Wall, WSW = White Side Wall, OWL = Outlined White Letters.

Load Index

128

The load index (LI) is a 2- or 3-digit number that correlates to the maximum amount of weight the tire can carry. For example, a tire with a load index of 87 indicates that the tire can carry a maximum load of 1,201 lbs. In this particularly example, 4 tires (each with a load index of 87) can carry a maximum of 4,804 lbs. Refer to your vehicle owner's manual for the recommended minimum load index.

Speed Rating
A guide to buying tires

Speed rating (SR) indicates the maximum speed the tire can achieve. Higher speed ratings are typically associated with better handling capabilities. Refer to your vehicle owner's manual for the recommended minimum speed rating.

Load Range/Ply Rating
Types of tires

D/8PLY

Ply rating, more commonly referred to as load range, represents the strength and durability of the tire. Higher ratings may indicate your tires can handle heavier loads.

UTQG

Not Available

To help consumers evaluate their tires, the U.S. National Highway Traffic Safety Administration (NHTSA) created the Uniform Tire Quality Grading System (UTQG). The UTQG rates tires are rated on their tread-wear, traction performance, and temperature resistance. The grade for each of these can be found on the sidewall of your tire (except for winter tires and certain light truck tires). Click here to learn more.

Max Single Load(lbs)

3970

The maximum load this tire will support. Remember to multiply this number by the number of tires installed on your vehicle to get the maximum carrying capacity. This number is directly related to the Load Index.

Max Single Air Pressure(PSI)

Not Available

The maximum air pressure this tire will support. This does not represent the amount of air pressure your tires should have at all times. Consult with your owner's manual to determine the best air pressure you should use for your vehicle.

Tread Depth

21.0

The amount of tread on the tire. Once the tire is worn to 2/32nds, it is considered fully used and should be replaced at that time. Most tires will have tire indicators in the grooves of the tire to help you determine when the tires are worn down to 2/32nds.

Tread Design

Nondirectional

The pattern of the grooves, lugs, voids, and sipes on a tire's surface. This design affects the tire's traction, handling, and noise characteristics. Common types include symmetrical (uniform pattern across the tire), asymmetrical (different patterns on the inside and outside for varied road conditions), and directional (designed to rotate in one direction for improved wet traction and hydroplaning resistance).

Rim Width Range

11.0-13.0

The approved wheel rim width range this tire will support.

Measured Rim Width

12.0

The recommended wheel width as recommended by the tire manufacturer to get the best wear us performance for this tire.

Section Width

15.4

The measurement from sidewall to sidewall.

Tread Width

Not Available

The measurement from one side of the tread to the other side of the tread.

Overall Diameter

37.87

The height of the tire when fully inflated.

Manufacturer Part Number

170239006

Manufacturer part number (sku)

Financing

You can pre-qualify to finance your tires, or you can simply choose Affirm at check-out. Fill out your information and choose the monthly payment that works best for you!

Select 3, 6 or 12 monthly payments, with rates from 10% - 36% APR. 18 months financing available for orders over $1000.00

Checking your eligibility won't affect your credit. You will receive an immediate answer from Affirm.

Affirm has no hidden fees or costs and is completely secure.
Quick and easy, real tire financing, real fast! You can apply in advance and know you can shop for tires when you are ready.

To learn more visit Buy With Affirm or read their convenient Affirm FAQ's. All credit decisions are made by Affirm.

To contact Affirm regarding your account, please call 1-855-423-3729.

No hidden fees

Affirm has no hidden fees or costs and is completely secure

Flexible

You choose the payment schedule that works for you

Quick and easy

Fill out your information and get a real-time decision

Pay over time

Choose the payment plan that works best for you

Learn more about Affirm tire financing options

No Credit? No problem!

Lease your tires with Katapult!

With a small down payment, and easy payments you can lease your tires. Payments are coordinated with your payday. Read more here about how Katapult works.

No credit required

Simple initial payment

No late fees ever

Payoff early is desired

Learn more about Katapult lease-to-own tire financing

Size Details

Size	Load Index/ Speed index	UTQG	Load Range/Ply Rating	Overall Diameter	Section Width	Rim Width Min	Rim Width Max	Rim Width Meas	Tread Depth (in)	Max Single Air Pressure (PSI)	Max Single Load (lbs)	Max Dual Air Pressure (PSI)	Max Dual Load (lbs)	MFG #
30X9.50R15	104Q	-	C/6PLY	29.6	9.6	6.5	8.5	7.5	19.0	50	1985	-	-	170122034
31X10.50R15	109Q	-	C/6PLY	30.7	10.7	7.0	9.0	8.5	20.0	50	2270	-	-	170110034
32X11.50R15	113Q	-	C/6PLY	31.5	11.7	8.0	10.0	9.0	20.0	50	2535	-	-	170130034
33X12.50R15	108Q	-	C/6PLY	32.7	12.2	8.5	11.0	10.0	21.0	35	2205	-	-	170107034
33X12.50R20	119Q	-	F/12PLY	32.7	12.5	8.5	11.0	10.0	21.0	80	3000	-	-	170230006
35X12.50R15	113Q	-	C/6PLY	34.5	13.1	8.5	11.0	10.0	21.0	35	2535	-	-	170113034
35X12.50R17	121Q	-	E/10PLY	34.5	12.6	8.5	11.0	10.0	21.0	65	3195	-	-	170255034
35X12.50R18	118Q	-	D/8PLY	34.6	12.7	8.5	11.0	10.0	21.0	50	2910	-	-	170229006
35X12.50R20	121Q	-	E/10PLY	34.6	12.4	8.5	11.0	10.0	21.0	65	3195	-	-	170128006
35X12.50R20	125Q	-	F/12PLY	34.6	12.4	8.5	11.0	10.0	21.0	80	3640	-	-	170148006
35X12.50R22	117Q	-	E/10PLY	34.76	12.3	8.5	11.0	10.0	21.0	65	2835	-	-	170132006
35X12.50R22	121Q	-	F/12PLY	34.7	12.3	8.5	11.0	10.0	21.0	80	3195	-	-	170231006
35X13.50R20	121Q	-	E/10PLY	34.5	13.2	8.5	11.0	11.0	21.0	65	3195	-	-	170141006
37X12.50R17	124Q	-	D/8PLY	36.8	13.0	8.5	11.0	10.0	22.0	50	3525	-	-	170129006
37X12.50R17	124K	-	D/8PLY	36.7	13.0	8.5	11.0	10.0	22.0	50	3525	-	-	170157006
LT37X12.5R17	124Q	-	D/8PLY	36.7	13.0	8.5	11.0	10.0	22.0	50	3525	-	-	170308006
37X12.50R20	126Q	-	E/10PLY	36.6	12.6	8.5	11.0	10.0	21.0	65	3750	-	-	170138006
LT37X12.5R20	126Q	-	E/10PLY	36.6	12.6	8.5	11.0	10.0	21.0	65	3750	-	-	170309006
37X13.50R17	121Q	-	E/10PLY	36.7	13.3	8.5	11.0	11.0	22.0	50	3195	-	-	170137006
37X13.50R18	124Q	-	D/8PLY	36.7	13.3	8.5	11.0	11.0	22.0	50	3525	-	-	170139006
37X13.50R18	124K	-	D/8PLY	36.7	13.3	8.5	11.0	11.0	22.0	50	3525	-	-	170158006
37X13.50R20	127Q	-	E/10PLY	36.8	13.3	8.5	12.0	11.0	21.0	65	3860	-	-	170134006
37X13.50R22	123Q	-	E/10PLY	36.8	13.4	8.5	12.0	11.0	21.0	65	3415	-	-	170140006
38X13.50R20	123Q	-	D/8PLY	38.1	13.6	8.5	11.0	11.0	21.0	50	3415	-	-	170143006
38X15.50R18	128Q	-	D/8PLY	37.87	15.4	11.0	13.0	12.0	21.0	-	3970	-	-	170239006
38X15.50R20	128Q	-	E/10PLY	37.8	15.4	11.0	13.0	12.0	21.0	65	3970	-	-	170144006
40X13.50R17	121Q	-	C/6PLY	39.7	13.6	8.5	11.0	11.0	22.0	35	3195	-	-	170142006
LT40X13.5R17	121Q	-	C/6PLY	39.7	13.6	8.5	11.0	11.0	22.0	35	3195	-	-	170307006
LT215/85R16	115/112Q	-	E/10PLY	30.6	8.5	5.5	7.0	6.0	18.5	80	2680	80	2470	170126006
LT235/85R16	120/116Q	-	E/10PLY	31.8	9.6	6.0	7.5	6.5	18.0	80	3042	80	2778	170109006
LT245/75R16	120/116Q	-	E/10PLY	30.7	9.6	6.5	8.0	7.0	18.0	80	3042	80	2778	170112006
LT265/70R17	121/118Q	-	E/10PLY	31.9	10.7	7.0	8.5	8.0	19.0	80	3195	80	2910	170102034
LT265/75R16	123/120Q	-	E/10PLY	31.8	10.7	7.0	8.0	7.5	19.0	80	3415	80	3085	170106034
LT265/75R16	123/120K	-	E/10PLY	31.9	10.7	7.0	8.0	7.5	20.0	80	3415	-	-	170150034
LT275/65R18	123/120Q	-	E/10PLY	32.2	10.9	7.5	9.0	8.0	19.0	80	3415	80	3085	170121034
LT275/65R18	123/120K	-	E/10PLY	32.3	10.9	7.5	9.0	8.0	20.0	80	3415	-	-	170155034
LT275/65R20	126/123Q	-	E/10PLY	34.4	10.9	7.5	9.5	8.0	20.0	80	3750	80	3415	170127006
LT275/65R20	126/123Q	-	E/10PLY	34.4	10.9	7.5	9.5	8.0	19.5	-	3750	-	-	170159006
LT275/70R18	125/122P	-	E/10PLY	33.3	11.3	7.0	9.0	8.0	20.0	80	3640	80	3305	170111034
LT275/70R18	125/122K	-	E/10PLY	33.3	11.3	7.0	8.5	8.0	20.0	80	3640	-	-	170152034
LT285/65R18	125/122Q	-	E/10PLY	32.9	11.8	8.0	10.0	8.5	19.0	80	3640	80	3305	170118034
LT285/70R17	121/118Q	-	E/10PLY	33.0	11.5	7.5	9.0	8.5	19.0	80	3195	80	2910	170114034
LT285/70R17	121/118Q	-	E/10PLY	33.0	11.5	7.5	9.0	8.5	19.0	80	3195	-	-	170306034
LT285/75R16	126/123Q	-	E/10PLY	32.9	11.2	7.5	9.0	8.0	19.0	80	3750	80	3415	170108034
LT285/75R16	126/123K	-	E/10PLY	33.0	11.2	7.5	9.0	8.0	20.0	80	3750	-	-	170151034
LT295/55R20	123/120Q	-	E/10PLY	33.0	12.3	8.0	10.0	9.5	20.0	80	3415	80	3085	170135006
LT295/60R20	126/123Q	-	E/10PLY	34.2	11.5	8.0	10.0	8.5	20.0	80	3750	80	3415	170104006
LT295/65R20	129/126Q	-	E/10PLY	35.4	11.7	8.0	10.0	8.5	20.0	80	4080	80	3750	170105006
LT295/65R20	129/126K	-	E/10PLY	35.4	11.7	8.0	10.0	8.5	20.0	80	4080	-	-	170149006
LT295/70R17	121/118Q	-	E/10PLY	33.4	12.0	7.5	10.0	8.5	21.0	80	3195	80	2910	170115034
LT295/70R18	129/126P	-	E/10PLY	34.4	12.0	7.5	10.0	8.5	21.0	80	4080	80	3750	170145034
LT305/55R20	121/118Q	-	E/10PLY	33.5	12.2	8.5	11.0	9.5	20.5	80	3195	-	-	170116006
LT305/55R20	125/122Q	-	F/12PLY	33.5	12.4	8.5	11.0	9.5	21.0	80	3640	80	3305	170146006
LT305/60R18	121/118Q	-	E/10PLY	32.6	12.0	8.5	11.0	9.0	21.0	65	3195	65	2910	170123034
LT305/60R18	126/123Q	-	F/12PLY	32.7	12.0	8.5	11.0	9.0	21.0	80	3750	80	3415	170147034
LT305/65R17	121/118Q	-	E/10PLY	32.6	12.3	8.5	11.0	9.0	21.0	65	3195	65	2910	170136006
LT305/70R16	124/121Q	-	E/10PLY	32.9	12.3	8.0	9.5	9.0	20.0	65	3525	65	3195	170120034
LT305/70R16	124/121K	-	E/10PLY	32.9	12.3	8.0	9.5	9.0	20.0	65	3525	-	-	170154034
LT305/70R18	126/123Q	-	E/10PLY	35.0	12.4	8.5	10.0	9.0	21.0	65	3750	65	3415	170125034
LT305/70R18	126/123K	-	E/10PLY	35.0	12.4	8.5	10.0	9.0	21.0	65	3750	-	-	170156034
LT315/70R17	121/118Q	-	E/10PLY	34.5	12.6	8.0	11.0	9.5	21.0	65	3195	65	2910	170119034
LT315/75R16	127/124Q	-	E/10PLY	34.5	12.6	8.0	11.0	8.5	20.5	65	3860	65	3525	170117034
LT315/75R16	127/124K	-	E/10PLY	34.5	12.6	8.0	11.0	8.5	21.0	65	3860	-	-	170153034
LT315/75R16	127/124Q	-	E/10PLY	34.5	12.6	8.0	11.0	8.5	21.0	65	3860	-	-	170310034
LT325/50R22	122Q	-	E/10PLY	35.1	12.9	9.0	12.0	10.0	21.0	10	3305	65	-	170133006
LT325/65R18	127/124Q	-	E/10PLY	34.6	13.7	9.0	12.0	9.5	21.0	65	3860	65	3525	170124034
LT325/65R18	127Q	-	E/10PLY	34.6	12.7	9.0	12.0	9.5	21.0	65	3860	-	-	23669