The 2015 GMC Trucks Sierra 2500 HD sits squarely in the heavy-duty pickup market, built for serious work while still offering trim-level variety that ranges from straightforward truck duty to a more upscale Denali presentation. That matters when choosing tires, because this Sierra 2500 HD uses three different primary radial sizes: 245/75R17, 265/70R18, and 265/60R20. The key decision is not bias-ply versus radial, but identifying the exact sub-model and wheel diameter first. Once that is settled, the tire choice becomes a matter of matching the truck's existing wheel setup, intended use, and preferred look, especially on trucks that may have had wheel or suspension changes over time.
Which Tire Size Is Right for The 2015 GMC Trucks Sierra 2500 HD
Three primary tire sizes apply to the 2015 GMC Trucks Sierra 2500 HD, and they vary by sub-model and wheel diameter. The first step is confirming the exact trim and whether the truck is currently on 17-inch, 18-inch, or 20-inch wheels, since tire selection starts with matching the correct rim diameter before comparing tread style, load capability, or appearance.
The 245/75R17 size uses a modern metric format: 245 is the nominal section width in millimeters, 75 is the aspect ratio, R identifies radial construction, and 17 is the wheel diameter in inches. On the 2015 GMC Trucks Sierra 2500 HD, this size is one of the primary heavy-duty radial fitments and is tied to 17-inch wheels. Available product choice in this size includes a BFGoodrich All-Terrain T/A KO2 with raised white letter styling. This is the size to evaluate when the truck is equipped with 17-inch wheels and the goal is maintaining the proper heavy-duty tire format.
The 265/70R18 size is a metric radial format in which 265 indicates nominal section width in millimeters, 70 is the aspect ratio, and 18 is the required wheel diameter in inches. For the 2015 GMC Trucks Sierra 2500 HD, this size is shared across multiple sub-models, making it one of the most broadly used fitments in the range. Its role is different from the 17-inch and 20-inch options because wheel diameter must already match before any tire can be considered. This size makes sense when the truck carries 18-inch wheels and the buyer wants to stay aligned with that original fitment path.
The 265/60R20 size follows the same modern metric radial convention, with 265 millimeters of nominal section width, a 60-series profile, and a 20-inch wheel requirement. On the 2015 GMC Trucks Sierra 2500 HD, this size applies to trims equipped with 20-inch wheels and gives the truck a distinctly different wheel-and-tire presentation from the 17-inch and 18-inch setups. Because the aspect ratio and rim diameter differ from the other primary sizes, it should be treated as its own fitment path rather than a casual substitute. This is the size to verify when a Sierra 2500 HD is running factory-style or similar 20-inch wheels.
Tire fitment on the 2015 GMC Trucks Sierra 2500 HD depends on the exact sub-model because several trims use more than one wheel-and-tire combination. Checking the trim name and actual wheel diameter is the quickest way to narrow the correct tire size before comparing tire style or intended use.
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2015 GMC Trucks Sierra 2500 HD Base
The 2015 GMC Trucks Sierra 2500 HD Base uses either a 245/75R17 or 265/70R18 radial fitment, so wheel diameter is the deciding factor. Tire selection starts with confirming whether the truck is on 17-inch or 18-inch wheels, then choosing a tire that matches the truck's work use and overall setup.
The 2015 GMC Trucks Sierra 2500 HD Denali uses either 265/60R20 or 265/70R18 radial tires depending on wheel setup. That means Denali owners should verify whether the truck is carrying 18-inch or 20-inch wheels before looking at tire choices, especially if the truck has ever been changed from its original wheel package.
The 2015 GMC Trucks Sierra 2500 HD SLE has the widest fitment spread here, using 245/75R17, 265/70R18, or 265/60R20 radial tires. Because this trim can appear with three different wheel diameters, the smartest starting point is the wheel itself rather than the trim badge alone.
The 2015 GMC Trucks Sierra 2500 HD SLT uses either 265/60R20 or 265/70R18 radial tires. That gives the SLT two distinct wheel-based fitment paths, so confirming the current 18-inch or 20-inch wheel setup is essential before choosing a replacement tire.
The tire sizes listed on this page assume factory-standard vehicle configuration. The following modifications may affect tire fitment and are not reflected in this guide:
Suspension changes (lowering, lift kits, spring replacements)
Body alterations (fender modifications, custom bodywork)
If your vehicle has been modified from factory specifications, verify tire clearance before purchase.
Best 2015 GMC Trucks Sierra 2500 HD Tires for Sale
Available product selection for the 2015 GMC Trucks Sierra 2500 HD currently centers on 245/75R17, including a BFGoodrich All-Terrain T/A KO2 radial with raised white letter styling. In the product grid, compare size, load capability, rim-width compatibility, and sidewall presentation against the truck's actual wheel setup.
Owners of a 2015 GMC Trucks Sierra 2500 HD usually need to sort out the correct tire size by trim and wheel diameter first. These FAQs focus on fitment, rim sizing, product choice, appearance, and the checks worth making before regular road use.
Tire Size & Fitment
What tire size fits a 2015 GMC Trucks Sierra 2500 HD?
The 2015 GMC Trucks Sierra 2500 HD uses three primary tire sizes: 245/75R17, 265/70R18, and 265/60R20. All three are radial fitments, and the correct one depends on the truck's sub-model and wheel package rather than the model name alone.
Choosing the right size starts with the actual wheel diameter on the truck. A Base, SLE, SLT, or Denali can use different tire sizes, and some trims overlap, so the most practical check is the trim level plus whether the truck is on 17-inch, 18-inch, or 20-inch wheels.
What size rim does a 2015 GMC Trucks Sierra 2500 HD use?
A 2015 GMC Trucks Sierra 2500 HD can use 17-inch, 18-inch, or 20-inch rims depending on the tire size and sub-model configuration. The three matching primary tire sizes are 245/75R17 for 17-inch rims, 265/70R18 for 18-inch rims, and 265/60R20 for 20-inch rims.
Rim diameter is the first fitment detail to confirm because none of these sizes cross over from one wheel diameter to another. Checking the wheel itself, the sidewall of the current tire, and any past wheel changes helps prevent ordering a tire that matches the truck's trim name but not its actual setup.
Why does the 2015 GMC Trucks Sierra 2500 HD have more than one tire size?
The 2015 GMC Trucks Sierra 2500 HD has more than one tire size because different trims and wheel packages use different diameters. Base, Denali, SLE, and SLT models do not all share a single wheel-and-tire combination, so more than one primary fitment appears across the model range.
That means the truck should not be matched by year, make, and model alone. A quick trim check is useful, but the deciding detail is still the wheel diameter currently on the vehicle, especially if aftermarket wheels, dealer-installed upgrades, or previous owner changes may have altered the original package.
Choosing the Right Tire
What should I consider when choosing a 245/75R17 tire for a 2015 GMC Trucks Sierra 2500 HD?
Start by confirming that 245/75R17 is the actual size on the truck and that the wheel is a 17-inch rim. For this Sierra 2500 HD fitment, available product details include radial construction, a raised white letter sidewall, a 6.5 to 7.5 inch rim-width range, and a maximum load rating of 3,195 lbs @ 80 psi.
Those details help narrow the right choice based on how the truck is used. A heavy-duty pickup should have a tire that matches wheel width, load demands, and intended driving conditions, so compare the truck's current setup carefully before choosing between appearance, tread character, and specification differences.
What sidewall styles are available for 2015 GMC Trucks Sierra 2500 HD tires?
Among the currently available products for this 2015 GMC Trucks Sierra 2500 HD fitment, the visible sidewall style is RWL, or raised white letter. That sidewall treatment appears on the available 245/75R17 BFGoodrich All-Terrain T/A KO2 radial offering.
Sidewall style is partly an appearance decision, but it should come after confirming the correct tire size and wheel diameter. On a truck like the Sierra 2500 HD, the visual look may matter, yet load capability, construction, and compatibility with the existing wheel package still deserve priority.
What brands offer tires for the 2015 GMC Trucks Sierra 2500 HD?
The currently available product selection for the 2015 GMC Trucks Sierra 2500 HD includes BFGoodrich. In the 245/75R17 fitment, that brand appears as the All-Terrain T/A KO2 radial, which combines a heavy-duty light-truck specification with raised white letter sidewall styling.
Brand is only one part of the decision. The more important comparison points are the correct size for the truck, the wheel diameter already on it, the tire's construction and load capability, and whether the tread and sidewall style suit the way the Sierra 2500 HD is actually used.
Restoration & Appearance
Which tire should I choose for a period-style 2015 GMC Trucks Sierra 2500 HD?
A period-style approach on a 2015 GMC Trucks Sierra 2500 HD usually starts by staying with the truck's proper wheel diameter and primary tire size rather than trying to force a different look. The visual character changes noticeably between 245/75R17, 265/70R18, and 265/60R20 because each size belongs to a different wheel package.
Appearance choices make more sense after the fitment is settled. A truck kept close to its original presentation typically looks best with the size and wheel combination that matches its trim and stance, while any change in wheel diameter or tire profile should be checked carefully against clearance and overall proportion.
Does correct tire fitment matter for a 2015 GMC Trucks Sierra 2500 HD restoration?
Correct tire fitment matters because it affects both the truck's appearance and the way the wheel openings are visually filled. On a 2015 GMC Trucks Sierra 2500 HD, the right look depends first on using the proper 17-inch, 18-inch, or 20-inch fitment path tied to the truck's trim and wheel package.
Restoration-minded owners should verify what wheel and tire combination the truck carried when new if originality is important. Trim level, wheel package, and current modifications can all influence what looks appropriate, so factory literature or marque-specific references are worth checking before making an appearance-driven change.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2015 GMC Trucks Sierra 2500 HD?
Yes, modifications can affect tire fitment on a 2015 GMC Trucks Sierra 2500 HD. Aftermarket wheels, suspension lifts, leveling kits, lowering changes, or altered offsets can change the space available for 245/75R17, 265/70R18, or 265/60R20 tires, even when the size looks close on paper.
The safest approach is to verify the actual wheel diameter and width already on the truck, then check steering, fender, and suspension clearance through the full range of movement. A heavy-duty pickup can hide fitment issues until it is loaded or turned sharply, so physical inspection matters.
What should I inspect before driving a 2015 GMC Trucks Sierra 2500 HD on new tires?
Before driving a 2015 GMC Trucks Sierra 2500 HD on new tires, inspect basic installation details first: correct size, proper wheel diameter, inflation pressure, and secure mounting. It also makes sense to look over the wheels for damage and make sure the tires have adequate clearance at the fenders and suspension.
A short follow-up inspection after initial road use is just as important. Recheck pressure, look for any rubbing marks, and confirm that the truck tracks normally at speed and during turns, since a heavy-duty platform can reveal setup problems only after the tires have been driven and settled.
How should tires on a 2015 GMC Trucks Sierra 2500 HD be maintained?
Tires on a 2015 GMC Trucks Sierra 2500 HD should be maintained with regular pressure checks, visual inspections, and prompt attention to uneven wear, cuts, bulges, or cracking. Because this is a heavy-duty truck, the tire's condition under load matters just as much as simple tread depth.
Maintenance should also include checking for slow air loss and watching how the tires wear across the tread, especially if the truck tows, hauls, or sits for long periods. Keeping the wheel-and-tire setup matched to the truck's actual use helps preserve both ride quality and dependable road behavior.
