The 1989 GMC Trucks K1500 sits in the square-body pickup era that helped define GM half-ton 4x4 trucks for work, winter use, and everyday utility. Buyers looking after one today are often balancing original stance, practical road manners, and the tougher visual character that belongs on a late-1980s GMC truck. Tire fitment centers on two 16-inch radial sizes, with 225/75R16 used on regular cab models and 245/75R16 used on extended cab versions. Current choices here lean toward an all-terrain radial with raised white letters, so the main decision is confirming cab configuration first, then matching the truck's use, wheel width, and overall presentation.
Which Tire Size Is Right for The 1989 GMC Trucks K1500
The 1989 GMC Trucks K1500 uses two primary tire sizes, and the correct one depends on the truck's exact sub-model. Both sizes are radial tires built for 16-inch wheels, so the first step is confirming whether the truck is a regular cab or extended cab configuration. Once that is settled, the decision becomes choosing the right all-terrain product within that size and making sure the wheel width matches the tire's intended range.
Fit(s): Sierra Ext. Cab, Sierra SLE Ext. Cab, and Sierra SLX Ext. Cab
Construction: Radial|Rim: 16 in
245/75R16 is a metric radial size in which 245 identifies the nominal section width in millimeters, 75 is the aspect ratio, R denotes radial construction, and 16 is the wheel diameter in inches. On the 1989 GMC Trucks K1500, this size is used on extended cab sub-models and keeps the truck in a period-appropriate 16-inch light-truck format. Available options in this size include a BFGoodrich All-Terrain T/A KO2 with raised white letter styling. It is the size to evaluate when the truck carries extended cab fitment and the wheels fall within the proper width range.
Fit(s): Sierra Reg. Cab, Sierra SLE Reg. Cab, and Sierra SLX Reg. Cab
Construction: Radial|Rim: 16 in
225/75R16 is a metric radial size where 225 gives the nominal section width in millimeters, 75 is the aspect ratio, R indicates radial construction, and 16 designates the wheel diameter. On the 1989 GMC Trucks K1500, this size belongs to regular cab sub-models and shares the same 16-inch wheel diameter as the larger fitment. The available tire choice in this size is a BFGoodrich All-Terrain T/A KO2 with raised white letters, giving it a traditional truck appearance. It is the right size to review when keeping a regular cab truck in its proper fitment range.
Sub-model fitment matters on the 1989 GMC Trucks K1500 because tire size changes with cab configuration. Extended cab versions use one primary size, while regular cab versions use another, so confirming the exact Sierra, SLE, or SLX configuration is the first step before comparing tires.
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1989 GMC Trucks K1500 Sierra Ext. Cab
The 1989 GMC Trucks K1500 Sierra Ext. Cab uses the larger of the two primary radial fitments on a 16-inch wheel. Tire selection here centers on staying with that size, confirming wheel width, and choosing an all-terrain style that suits the truck's intended road and light off-road use.
The 1989 GMC Trucks K1500 Sierra Reg. Cab uses the narrower primary radial size on a 16-inch wheel. That makes the tire decision more about preserving the correct regular cab fitment and checking that the wheel setup still matches the tire's width requirements.
The 1989 GMC Trucks K1500 Sierra SLE Ext. Cab follows the extended cab tire fitment rather than the regular cab size. Choosing a tire for this sub-model means confirming the truck still carries its proper 16-inch wheel setup and selecting within the available all-terrain radial option.
The 1989 GMC Trucks K1500 Sierra SLE Reg. Cab uses the same primary tire size as the other regular cab versions. Tire choice is straightforward once the cab style is confirmed, with attention focused on correct size, wheel width compatibility, and the truck's intended driving use.
The 1989 GMC Trucks K1500 Sierra SLX Ext. Cab shares the extended cab tire fitment used elsewhere in the K1500 range. The practical next step is verifying that the truck still has the proper 16-inch wheels before selecting the available radial all-terrain tire in that size.
The 1989 GMC Trucks K1500 Sierra SLX Reg. Cab uses the regular cab radial tire size rather than the extended cab fitment. That keeps selection simple, but it is still worth checking wheel width and any later wheel or suspension changes before settling on 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 1989 GMC Trucks K1500 Tires for Sale
Available 1989 GMC Trucks K1500 tire choices center on BFGoodrich All-Terrain T/A KO2 radials in both primary sizes. Each uses a 16-inch rim and raised white letter styling, with size-specific differences in rim-width range, load capacity, and overall tire weight.
Owners of a 1989 GMC Trucks K1500 usually need to sort out the correct cab-specific tire size first, then compare 16-inch radial fitment, wheel compatibility, product details, and road-use checks before putting the truck back into regular service.
Tire Size & Fitment
What tire size fits a 1989 GMC Trucks K1500?
A 1989 GMC Trucks K1500 uses either 245/75R16 or 225/75R16, depending on the sub-model. Extended cab versions use 245/75R16, while regular cab versions use 225/75R16. Both are radial tires built for 16-inch wheels.
The key is matching the tire size to the truck's actual cab configuration, not just the K1500 nameplate. A truck that has had wheel, suspension, or stance changes over the years should also be checked carefully so the selected tire still suits the wheel width and available clearance.
What size rim does a 1989 GMC Trucks K1500 use?
The 1989 GMC Trucks K1500 uses a 16-inch rim with both of its primary tire sizes. That applies whether the truck uses 225/75R16 or 245/75R16, so rim diameter stays the same even though the tire width and overall size differ by sub-model.
Rim diameter is only part of the fitment picture, so it helps to confirm wheel width as well before replacing tires. The available 225/75R16 and 245/75R16 products have different rim-width ranges, which matters if the truck no longer wears its original-style wheels.
Do all 1989 GMC Trucks K1500 sub-models use the same tire size?
No, the 1989 GMC Trucks K1500 does not use one tire size across every covered sub-model. Sierra, Sierra SLE, and Sierra SLX regular cab versions use 225/75R16, while the corresponding extended cab versions use 245/75R16.
That split makes the sub-model more important than trim name alone when choosing tires. A quick check of the truck's cab style, wheel size, and any past modifications will usually prevent ordering the wrong size and help keep the K1500's stance and clearance where they belong.
Choosing the Right Tire
What should I consider when choosing a tire for a 1989 GMC Trucks K1500?
Start with the correct primary size for the truck's sub-model, since regular cab and extended cab K1500s do not use the same tire. From there, the main factors are radial construction, 16-inch wheel compatibility, rim-width range, load capacity, and how the truck is actually used.
A truck kept for road driving, seasonal use, or light trail work may call for a different emphasis than one maintained mainly for appearance. Matching the tire to the wheel setup and the truck's real duty cycle usually matters more than focusing on one specification in isolation.
What sidewall styles are available for 1989 GMC Trucks K1500 tires?
The available tires for the 1989 GMC Trucks K1500 use RWL sidewalls, which means raised white letters. That style suits the late-1980s truck look well and gives the K1500 a more traditional all-terrain appearance than a plain black sidewall would.
Sidewall style is partly an appearance decision, but it also affects how the truck presents from the curb. Anyone trying to preserve a period-style truck look may prefer the visual presence of raised white letters, while still needing to confirm that the tire size and wheel dimensions are correct.
What brands offer tires for the 1989 GMC Trucks K1500?
BFGoodrich is the available brand across both primary 1989 GMC Trucks K1500 tire sizes here. The tire series offered is the All-Terrain T/A KO2, a radial light-truck design with raised white letter sidewalls in both 225/75R16 and 245/75R16.
That keeps brand choice simple and shifts the focus to selecting the correct size for the truck's cab style. Comparing the two size-specific products by wheel-width range, load figure, and how the truck is actually driven will usually be more useful than looking for brand variation.
Restoration & Appearance
Which tire should I choose for a period-style 1989 GMC Trucks K1500?
A period-style 1989 GMC Trucks K1500 should start with the correct cab-specific size: 225/75R16 for regular cab models and 245/75R16 for extended cab models. Keeping the proper 16-inch radial fitment helps preserve the truck's stance and prevents the look from drifting away from late-1980s GMC proportions.
Appearance also comes from sidewall presentation, and the available raised white letter all-terrain style fits the era naturally. Anyone aiming for a highly exact restoration should still compare the truck against original literature, photos, or marque references before treating any current tire as an exact historical match.
Does correct tire fitment matter for a 1989 GMC Trucks K1500 restoration?
Correct tire fitment matters because the 1989 GMC Trucks K1500 uses different primary sizes across regular cab and extended cab versions. Using the proper size keeps the truck's visual balance closer to how the K1500 was intended to sit and helps avoid a mismatched restored appearance.
Fitment also affects practical details such as wheel-width suitability and available clearance. A restoration-minded owner should confirm the truck has the right 16-inch wheels and has not been altered with later suspension or wheel changes that could make a historically appropriate tire size harder to use.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1989 GMC Trucks K1500?
Yes, modifications can affect tire fitment on a 1989 GMC Trucks K1500 even when the truck still uses one of its original-style sizes. Aftermarket wheels, wheel-width changes, altered offset, lift kits, lowering, and worn suspension parts can all change how a 225/75R16 or 245/75R16 tire sits.
Checking the actual wheel setup matters before replacing tires on any older truck that may have been changed over time. It helps to confirm the wheel diameter and width first, then look for steering clearance, fender clearance, and any signs that the current tire has been rubbing under normal driving.
What should I inspect before driving a 1989 GMC Trucks K1500 on new tires?
Before road use, inspect the wheels for proper size and condition, verify the tires are inflated appropriately for the application, and look over the suspension and steering for worn parts. Lug hardware, valve stems, and any uneven wear patterns on the old tires also deserve attention.
A short test drive should include listening for rubbing and checking that the truck tracks and steers normally. Older pickups that see occasional use benefit from another quick walkaround after the first drive to confirm there is no air loss, contact issue, or settling problem at the front suspension.
How should tires on a collector-era 1989 GMC Trucks K1500 be maintained?
Tires on a collector-era 1989 GMC Trucks K1500 should be checked regularly for pressure, tread condition, cracking, bulges, cuts, and signs of slow air loss. Even a truck that is driven lightly can age its tires over time, so condition matters just as much as remaining tread depth.
Storage habits also influence tire life on an older pickup. Keeping the truck away from prolonged sunlight, moisture, and ozone sources helps, and it is wise to inspect the tires before each meaningful drive rather than assuming low annual mileage means the tires are still road-ready.
