The 2020 GMC Trucks Sierra 1500 sits firmly in the modern full-size pickup category, balancing daily usability, towing and hauling duty, and trim-dependent personality that ranges from straightforward work-truck setups to more upscale and off-road-oriented versions. Tire selection matters because this Sierra 1500 uses six different primary radial sizes across 17-inch, 18-inch, 20-inch, and 22-inch wheel packages. That means the first step is confirming the exact sub-model and wheel diameter before comparing options. Among the available choices, sizing and load specification can matter more than brand variety, especially for owners trying to preserve the truck’s intended stance, clearance, and everyday drivability.
Which Tire Size Is Right for The 2020 GMC Trucks Sierra 1500
The 2020 GMC Trucks Sierra 1500 uses six primary tire sizes, and the correct one depends on the exact sub-model and wheel diameter. These are all radial fitments, but they span 17-inch, 18-inch, 20-inch, and 22-inch rims, so confirming the truck’s current wheel setup comes first. Once that is settled, the decision shifts to the right load specification, tire character, and intended use for that size.
265/65R18 is a metric radial size that uses a 265-millimeter section width, a 65-series aspect ratio, and an 18-inch rim diameter. On the 2020 GMC Trucks Sierra 1500, this size is one of the 18-inch radial fitments and appears on certain trim levels rather than across the entire model range. It suits buyers who need to stay with the truck’s 18-inch wheel package while keeping the overall tire profile appropriate to that setup. Before choosing within this size, verify the trim and wheel combination currently on the truck, especially if it has been changed from stock-style wheels.
275/60R20 is a metric radial size with a 275-millimeter section width, a 60-series profile, and a 20-inch rim diameter. This is one of the more widely used sizes on the 2020 GMC Trucks Sierra 1500, appearing across several sub-models, so it often becomes the key fitment to confirm on trucks equipped with 20-inch wheels. Its role is tied to the larger wheel package, not to every Sierra 1500 configuration. Buyers should match this size to the actual wheel diameter on the truck first, then compare tire type and load details that suit how the truck is driven.
275/65R18 is a metric radial size that combines a 275-millimeter section width with a 65-series profile on an 18-inch rim. On the 2020 GMC Trucks Sierra 1500, this size is associated with a specific sub-model application rather than broad use across the lineup. Available product choice in this size leans toward an all-terrain presentation, including BFGoodrich All-Terrain T/A KO2 with raised white letter styling. It is the right size to evaluate when the truck already runs the corresponding 18-inch wheel setup and the owner wants a more truck-oriented tread style without moving outside the original size family.
255/70R17 is a metric radial tire size with a 255-millimeter section width, a 70-series aspect ratio, and a 17-inch rim diameter. Within the 2020 GMC Trucks Sierra 1500 range, it belongs to selected 17-inch wheel applications and should not be confused with the other 17-inch size used on some trims. Its dimensions make it part of a specific factory-style wheel and tire combination rather than a universal Sierra 1500 fitment. The practical decision here is confirming that the truck actually uses this 17-inch setup before comparing tire choices or considering any move to a different wheel package.
265/70R17 is a metric radial size that uses a 265-millimeter section width, a 70-series profile, and a 17-inch rim. For the 2020 GMC Trucks Sierra 1500, it is one of the 17-inch fitments used on selected sub-models, so correct identification matters even among trucks that share the same wheel diameter. Product availability in this size includes BFGoodrich All-Terrain T/A KO2 options with raised white letter sidewalls and different load specifications. This size is worth close attention for owners who want to keep a 17-inch truck setup while matching the tire’s capability and character to the way the Sierra is used.
275/50R22 is a metric radial size with a 275-millimeter section width, a 50-series profile, and a 22-inch rim diameter. On the 2020 GMC Trucks Sierra 1500, this size belongs to certain higher-wheel-package applications and gives the truck a distinctly different fitment direction from the 17-inch and 18-inch combinations. Because the sidewall profile is lower and the wheel diameter is larger, wheel confirmation is especially important before selecting a replacement. Buyers considering this size should focus first on preserving the truck’s existing 22-inch setup and then compare tire choices that match that wheel package and intended road use.
Tire fitment for the 2020 GMC Trucks Sierra 1500 varies significantly by sub-model, and several trims use more than one size. Checking the exact trim matters because the lineup spans four wheel diameters and multiple metric radial sizes that are not interchangeable without confirming the full wheel and tire setup.
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2020 GMC Trucks Sierra 1500 AT4
The 2020 GMC Trucks Sierra 1500 AT4 uses 18-inch and 20-inch radial tire fitments, including a distinct 275/65R18 application. That makes wheel confirmation especially important before choosing between a more road-oriented replacement and an all-terrain style tire within the proper size.
The 2020 GMC Trucks Sierra 1500 Base uses 17-inch radial tire sizes, but not just one fitment. Tire selection starts with confirming which 17-inch size is on the truck now, then matching the replacement to the wheel package and intended duty.
The 2020 GMC Trucks Sierra 1500 Denali uses larger-wheel radial fitments, including 20-inch and 22-inch applications. That means replacement tire choice is closely tied to the truck’s actual wheel diameter and whether the goal is to preserve its existing stance and road-going character.
The 2020 GMC Trucks Sierra 1500 Elevation uses either a 20-inch or 22-inch radial tire setup. The key step is verifying which wheel package is on the truck before comparing replacement tires, since those two sizes belong to different overall fitment combinations.
The 2020 GMC Trucks Sierra 1500 SLE has the widest tire-size spread in the lineup, covering 17-inch, 18-inch, 20-inch, and 22-inch radial applications. For this trim, a simple trim-name check is not enough; the actual wheel diameter and current size on the truck need to be confirmed first.
The 2020 GMC Trucks Sierra 1500 SLT uses 18-inch, 20-inch, and 22-inch radial tire fitments depending on wheel package. Choosing the right replacement means matching the truck’s current size first, then comparing tire style and specification within that correct fitment.
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 2020 GMC Trucks Sierra 1500 Tires for Sale
Available product coverage for the 2020 GMC Trucks Sierra 1500 is concentrated in 265/70R17 and 275/65R18, with BFGoodrich All-Terrain T/A KO2 options and raised white letter sidewalls. These choices are all radial truck tires, and the key comparison points are size, load specification, and rim-width compatibility.
These FAQs focus on the real tire decisions for the 2020 GMC Trucks Sierra 1500, including trim-specific sizing, wheel diameter, radial fitment, product choice, appearance, and the checks to make before putting the truck back on the road.
Tire Size & Fitment
What tire size fits a 2020 GMC Trucks Sierra 1500?
The 2020 GMC Trucks Sierra 1500 uses six primary tire sizes: 255/70R17, 265/70R17, 265/65R18, 275/65R18, 275/60R20, and 275/50R22. All of them are radial sizes, and the correct fitment depends on the truck’s exact sub-model and wheel package rather than the Sierra 1500 name alone.
The practical step is to confirm the trim and the actual wheel diameter on the truck before selecting a replacement. Some trims use more than one size, and trucks that have had wheel changes or accessory packages added can no longer be judged by trim badge alone.
What size rim does a 2020 GMC Trucks Sierra 1500 use?
A 2020 GMC Trucks Sierra 1500 can use 17-inch, 18-inch, 20-inch, or 22-inch rims, depending on sub-model and tire size. The tire size itself confirms the rim diameter: 255/70R17 and 265/70R17 use 17-inch rims, 265/65R18 and 275/65R18 use 18-inch rims, 275/60R20 uses a 20-inch rim, and 275/50R22 uses a 22-inch rim.
That makes wheel-diameter verification one of the most important fitment checks on this truck. Before ordering tires, read the size from the current sidewall and compare it to the actual wheels on the vehicle, especially if the Sierra has aftermarket wheels or a trim-specific appearance package.
Why does the 2020 GMC Trucks Sierra 1500 have more than one tire size?
The 2020 GMC Trucks Sierra 1500 spans several trims, and those trims use different wheel packages that call for different radial tire sizes. Base, SLE, AT4, SLT, Denali, and Elevation configurations do not all share the same wheel diameter, so the tire fitment changes with the package.
That variation means replacement tires should be chosen by the truck’s exact current setup, not by assuming every Sierra 1500 uses the same size. Looking at the sidewall, checking the trim, and confirming whether the wheels are original or changed will prevent most fitment mistakes.
Choosing the Right Tire
What should I consider when choosing a 2020 GMC Trucks Sierra 1500 tire?
Start with the correct size for the truck’s trim and wheel diameter, since the 2020 GMC Trucks Sierra 1500 uses six different radial fitments. After that, compare the tire’s intended character, load specification, and whether the truck is being used mainly for highway driving, mixed use, or more truck-oriented service.
A Sierra 1500 on 17-inch or 18-inch wheels may call for a very different tire choice than one on 22-inch wheels, even before brand enters the picture. Matching the replacement to the truck’s actual wheel setup and day-to-day use will usually matter more than chasing a generic one-size-fits-all answer.
What sidewall styles are available for 2020 GMC Trucks Sierra 1500 tires?
Among the currently covered Sierra 1500 products, the available sidewall style is RWL, or raised white letter. That style appears on BFGoodrich All-Terrain T/A KO2 offerings in 265/70R17 and 275/65R18, giving those sizes a more traditional truck appearance than a plain black sidewall would.
Sidewall style affects appearance more than fitment, so it should be chosen only after the correct size is confirmed. On a truck like the Sierra 1500, raised white letters can suit an all-terrain look, but the right rim diameter, load specification, and intended use still need to come first.
What brands offer tires for the 2020 GMC Trucks Sierra 1500?
Current product coverage for the 2020 GMC Trucks Sierra 1500 includes BFGoodrich. The available listings are in BFGoodrich’s All-Terrain T/A KO2 series for 265/70R17 and 275/65R18, both offered as radial truck tires with raised white letter sidewalls.
Brand should be considered alongside the truck’s actual size, wheel fitment, and intended use rather than as a separate shortcut. On this Sierra 1500 page, the available BFGoodrich options are most relevant for owners running those specific 17-inch or 18-inch fitments and looking for an all-terrain presentation.
Restoration & Appearance
Which tire should I choose for a period-style 2020 GMC Trucks Sierra 1500?
For a 2020 GMC Trucks Sierra 1500, a period-style approach usually means keeping the truck in the same tire size and wheel diameter it already uses rather than trying to force an older-looking fitment onto it. The available BFGoodrich All-Terrain T/A KO2 options in 265/70R17 and 275/65R18 can support a distinctly truck-oriented appearance within those correct sizes.
Appearance should follow fitment, not replace it. Preserving the original-style wheel package, sidewall profile, and overall stance generally does more for the truck’s visual authenticity than changing to a different diameter, and trim-specific factory references are still worth checking when exact presentation matters.
Does correct tire fitment matter for a 2020 GMC Trucks Sierra 1500 restoration or refresh?
Yes, correct tire fitment matters because the 2020 GMC Trucks Sierra 1500 was offered with several distinct wheel and tire combinations. Keeping the right size family for the truck’s trim helps preserve its intended stance, wheel-to-tire proportion, and the visual character that separates a Base, AT4, Denali, or other configuration.
Even on a newer collector-minded truck, the wrong diameter or profile can change the look immediately. A careful refresh starts by confirming the existing wheel package, then selecting a tire that matches that setup instead of treating all Sierra 1500 trims as though they shared one universal fitment.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2020 GMC Trucks Sierra 1500?
Yes, modifications can affect tire fitment on a 2020 GMC Trucks Sierra 1500. Aftermarket wheels, suspension changes, leveling kits, lifts, or body alterations can change the wheel width, diameter, offset, and available clearance, which may alter how a factory-size tire sits and how safely an alternative size can be evaluated.
That is especially important on a truck that already spans 17-inch through 22-inch factory-style fitments. Any Sierra 1500 that has been modified should be checked for steering clearance, fender clearance, and actual wheel dimensions before a replacement tire is chosen simply by trim name or door-sticker assumption.
What should I inspect before driving a 2020 GMC Trucks Sierra 1500 on new tires?
Before driving a 2020 GMC Trucks Sierra 1500 on new tires, inspect the wheel condition, verify the tire size against the truck’s wheel package, and confirm proper inflation. It is also smart to look over valve stems, lug torque, tread seating, and any signs that the new tires are too close to suspension, fender, or steering components.
A short initial road test can reveal rubbing, vibration, or pull that is easier to correct early. After a few miles, recheck air pressure and visually confirm that the tires are wearing evenly and clearing the truck properly at full steering lock and normal suspension movement.
How often should tires on a 2020 GMC Trucks Sierra 1500 be inspected?
Tires on a 2020 GMC Trucks Sierra 1500 should be inspected regularly, not just when they look low or worn. Frequent checks for pressure loss, tread wear, cuts, bulges, punctures, and uneven shoulder wear are especially important on a truck that may tow, haul, or alternate between highway and rougher-duty use.
Monthly visual inspections are a sensible baseline, with additional checks before longer trips or heavy-load use. A Sierra that sits for periods should also be watched for flat spotting or age-related deterioration, since low-use vehicles can develop tire issues even when tread depth still looks serviceable.
