2021 GMC Trucks Tire Fitment Guide

2021 GMC Trucks vehicles use 21 tire sizes across eight model lines: 235/55R20, 255/65R17, 245/65R17, and 235/65R18 for Acadia; 265/65R17, 255/55R20, and 265/60R18 for Canyon; 265/60R20, 265/65R18, 275/60R20, 275/65R18, 255/70R17, 265/70R17, and 275/50R22 for Sierra 1500; 275/65R20, 275/70R18, 245/75R17, and 265/70R17 for Sierra 2500 HD; 235/80R17, 275/65R20, and 275/70R18 for Sierra 3500 HD; 235/50R19, 225/65R17, and 225/60R18 for Terrain; and 265/65R18, 275/60R20, and 275/50R22 for Yukon and Yukon XL.

Rim diameters across the full 2021 GMC Trucks range run from 17 to 22 inches, so year and make alone are not enough to choose correctly. Where product fitment details are available, rim-width ranges include 6.0-7.5 inches for 235/80R17, 6.0-8.0 for 225/65R17, 6.5-7.5 for 245/75R17, 7.0-8.0 for 245/65R17, 7.0-9.0 for 255/65R17 and 265/70R17, 7.0-9.0 for 275/70R18, and 7.5-9.5 for 275/65R18 and 275/65R20. Match the model first, then the wheel diameter, then the exact size on the tire sidewall.

On a 2021 GMC Trucks tire, 255/65R17 is a metric radial code. The 255 is the nominal section width in millimeters, 65 is the aspect ratio, the R means radial construction, and 17 is the rim diameter in inches. Within the 2021 GMC Trucks range, that size is used on the Acadia rather than across every model line.

That decoding matters because a 255/65R17 is not interchangeable with another 17-inch GMC size just because the rim diameter matches. Width, sidewall height, and load capacity all change with the full size code. If you are replacing one tire or an entire set on a 2021 GMC Trucks Acadia, read the complete sidewall marking and verify the wheel width as well, since the available KO2 fitment is built for a 7.0-9.0 inch rim-width range.

No. 2021 GMC Trucks spans crossovers, midsize pickups, full-size pickups, and heavy-duty trucks, and the tire sizes vary accordingly. A few sizes are shared within related groups, such as 265/65R18, 275/60R20, and 275/50R22 across Sierra 1500, Yukon, and Yukon XL, plus 275/65R20 and 275/70R18 across Sierra 2500 HD and Sierra 3500 HD, but there is no one size that fits the entire GMC lineup for 2021.

That means the right buying process starts with the exact model name, not just the brand and year. Even within one model line, wheel packages can move you from a 17-inch tire to an 18-, 20-, or 22-inch tire. If your 2021 GMC Trucks vehicle has had wheels changed at some point, compare the sidewall marking on the tire to the wheel diameter and the original fitment before making a replacement choice.

Available sidewall styles for 2021 GMC Trucks tires include RWL and RBL, depending on size. RWL appears on 255/65R17, 245/65R17, 275/65R18, 265/70R17, 275/70R18, and 245/75R17, while RBL appears on 275/65R20, 235/80R17, and 225/65R17. Those sidewall treatments all appear in BFGoodrich All-Terrain T/A KO2 applications for the sizes covered by current product offerings.

Sidewall style is usually a visual choice first, but it can also shape how closely the tire matches the look of a given GMC. A heavy-duty or off-road-oriented truck may look at home with raised white letters, while a black-letter sidewall can feel more understated on some SUV or work-truck applications. Since sidewall style changes by exact size, confirm the size you need before deciding which appearance best suits your 2021 GMC Trucks vehicle.

BFGoodrich is the brand currently covering the productized sizes for 2021 GMC Trucks on this page. The available sizes include 255/65R17, 245/65R17, 275/65R18, 265/70R17, 275/65R20, 275/70R18, 245/75R17, 235/80R17, and 225/65R17, all in the All-Terrain T/A KO2 series. Every one of those offerings is a radial tire.

That concentration around one brand and series means the main differences here are not brand-to-brand character, but the exact size, sidewall style, and load capacity tied to each application. If your 2021 GMC Trucks vehicle uses one of the sizes without a product shown here, start by confirming the original wheel diameter and tire size on the vehicle, then compare that against the model-specific fitment page for the most direct route to the right replacement.

The two 265/70R17 options for 2021 GMC Trucks are both BFGoodrich All-Terrain T/A KO2 radials with RWL sidewalls and an S speed rating, which carries a 112 mph ceiling. The differences are load capacity, inflation pressure, and weight: one carries 2,470 pounds at 50 psi and weighs 45.7 pounds, while the other carries 3,195 pounds at 80 psi and weighs 53.5 pounds. Both fit 7.0-9.0 inch rim widths.

That makes the choice less about appearance and more about how the truck is equipped and used. A Sierra 2500 HD or a heavily worked Sierra 1500 may call for the higher-capacity version, while another application may align with the lighter one. Check the tire currently on the truck, the load index on the sidewall, and the vehicle's factory placard before selecting between the two 265/70R17 versions.

Rim-width requirements for 2021 GMC Trucks vary by exact tire size. Available fitments include 255/65R17 on 7.0-9.0 inch rims, 245/65R17 on 7.0-8.0, 275/65R18 on 7.5-9.5, 265/70R17 on 7.0-9.0, 275/65R20 on 7.5-9.5, 275/70R18 on 7.0-9.0, 245/75R17 on 6.5-7.5, 235/80R17 on 6.0-7.5, and 225/65R17 on 6.0-8.0. Those ranges are tied to the size itself, not just the model.

The practical point is that sharing a rim diameter does not automatically mean two different tire sizes want the same wheel width. Before ordering, verify the wheel width on the vehicle and compare it to the acceptable range for the exact size you plan to run. That matters most on trucks where owners may have changed wheels or moved between factory wheel packages over time.

The 2021 GMC Trucks products shown here are modern radial truck and SUV tires, and none carries a tube-type marking. Their size markings appear as standard radial fitments without TT notation, so these applications are tubeless in the configurations represented here. That matches what most buyers would expect from late-model GMC wheels and radial tires.

Even so, the wheel itself still needs to be in proper condition for tubeless service. Check the bead seats, valve stems, and wheel condition before mounting a new tire, especially on a truck or SUV that sees towing, trail use, or long storage periods. If a 2021 GMC Trucks vehicle has aftermarket wheels, confirm those wheels are intended for the tire size and load range you plan to use.

A 2021 GMC Trucks vehicle should be stored on clean, properly inflated tires in a cool, dry space away from direct sunlight, electric motors, battery chargers, welders, and other ozone-producing equipment. Keep the tires off standing moisture and out of contact with petroleum products or solvents. If the vehicle will sit for long periods, move it periodically so weight is not resting on the same footprint month after month.

That routine helps reduce flat-spotting, preserves sidewall condition, and makes the vehicle more ready for service when driving season returns. Heavier models such as Sierra HD trucks and Yukon SUVs put more static weight on each tire, so inflation and storage surface quality matter even more. If the vehicle will be parked for an extended off-season, some owners also use stands to reduce constant loading on the tires.

Tires on a 2021 GMC Trucks vehicle should be judged by age and condition as much as by remaining tread. A sound rule is to begin careful evaluation once tires reach about five to seven years from the DOT date code, with replacement becoming a serious consideration as they approach ten years old even if tread depth still looks usable. Heat, sun exposure, storage habits, and sustained heavy loading can shorten that timeline.

That matters because many SUVs and trucks cover relatively low annual mileage, so a tire can age out long before it wears out. Check the DOT date on every tire, including the spare if one is carried, and look for cracking, hardening, or irregular wear. If the tires are several years old and the vehicle is used for towing, family travel, or longer highway trips, age deserves extra attention before the next drive.

Tires on a 2021 GMC Trucks vehicle should be inspected before every drive and more thoroughly before any extended outing. Look for cuts, punctures, sidewall cracking, bulges, uneven wear, embedded debris, and pressure loss. On heavier truck sizes, also pay attention to how the tire is carrying the load and whether shoulder wear or center wear suggests an inflation issue.

A quick walkaround catches many problems before they become a roadside failure. Add a deeper inspection at seasonal intervals, including tread depth checks and valve-stem condition, especially if the vehicle tows, sits for long periods, or runs higher-pressure heavy-duty tires. If one tire is wearing differently from the others on a 2021 GMC Trucks vehicle, treat that as a prompt to inspect alignment, suspension, and wheel condition too.

Yes, the available 2021 GMC Trucks tire products here are modern radial tires intended for normal road use, but their speed ratings and load ratings still matter. The sizes shown carry S and R speed ratings: S is rated to 112 mph, while R is rated to 106 mph. Examples include 255/65R17, 245/65R17, 265/70R17, 275/65R20, 245/75R17, 235/80R17, and 225/65R17 in S, plus 275/65R18 and 275/70R18 in R.

In real use, most 2021 GMC Trucks vehicles will be limited more by safe loading, suspension condition, brakes, road conditions, and driver judgment than by those speed ceilings. What matters most is choosing the exact size and load range the vehicle requires, then maintaining proper inflation. A highway-safe setup starts with matching the tire to the model's wheel package and intended duty, especially on Sierra HD applications.

Inflation pressure for 2021 GMC Trucks tires depends on the exact size and product. Available ratings include 255/65R17 at 2,600 pounds @ 65 psi, 245/65R17 at 2,405 pounds @ 65 psi, 275/65R18 at 3,415 pounds @ 80 psi, 265/70R17 at either 2,470 pounds @ 50 psi or 3,195 pounds @ 80 psi, 275/65R20 at 3,750 pounds @ 80 psi, 275/70R18 at 3,640 pounds @ 80 psi, 245/75R17 at 3,195 pounds @ 80 psi, 235/80R17 at 3,085 pounds @ 80 psi, and 225/65R17 at 2,150 pounds @ 65 psi.

Those figures are maximum load-and-pressure ratings for the tire, not automatic day-to-day inflation instructions for every GMC application. Use the vehicle's door-jamb placard or owner's manual for the factory target pressure, then confirm that the chosen tire's rating supports the way the vehicle is used. Never transfer a pressure figure from one 2021 GMC Trucks size to another just because the model family is similar.

Before a longer drive in a 2021 GMC Trucks vehicle, inspect every tire for cracking, punctures, sidewall bulges, irregular wear, and correct cold inflation pressure. Check the valve stems, look over the spare, and confirm that all four road tires match in size and service type. On trucks and SUVs that tow or carry significant weight, make sure the tires' load capacity and condition still suit the planned trip.

That tire inspection should be part of a broader pre-trip check that also covers brakes, fluids, steering, suspension, and lighting. A Sierra HD headed out with cargo or a Yukon loaded for family travel places different demands on its tires than a lightly used crossover, so trip preparation should reflect the vehicle's job. Catching a worn tire or pressure problem in the garage is far better than discovering it on the shoulder.