1991 GMC Trucks Jimmy Tires

The 1991 GMC Trucks Jimmy uses two primary tire sizes: 235/75R15 and 31X10.50R15. Both are radial tires for 15-inch wheels, and both apply to the Jimmy Base covered here. The difference is in the tire's overall sizing approach, with 235/75R15 using a metric format and 31X10.50R15 using a flotation-style light truck format.

Choosing between them starts with the setup already on the vehicle. A Jimmy wearing stock-style wheels and road-oriented proportions may point toward 235/75R15, while a taller light-truck stance may point toward 31X10.50R15. Wheel width, clearance, and any past changes to suspension or wheels should be checked before changing from one size to the other.

Both primary tire sizes for the 1991 GMC Trucks Jimmy use a 15-inch rim diameter. That means either 235/75R15 or 31X10.50R15 is built to mount on a 15-inch wheel, even though the two tires differ substantially in overall height and width.

Rim diameter is only the first checkpoint. The wheel's actual width matters too, because the available 235/75R15 products span several rim-width recommendations and the 31X10.50R15 all-terrain tire calls for a wider range. A quick look at the stamping on the wheel or a direct measurement helps confirm whether the wheel matches the tire you plan to use.

The 1991 GMC Trucks Jimmy Base shares the same two primary tire sizes used on this page: 235/75R15 and 31X10.50R15. Both are radial tires for 15-inch rims, so the sub-model itself does not force a different tire size choice here.

That does not mean every Jimmy Base on the road today is wearing the same setup. Many older trucks have seen wheel changes, suspension work, or a switch from a stock-style metric tire to a taller light-truck tire. Matching the new tire to the wheel currently on the vehicle is more important than assuming every Base model still carries its original-style dimensions.

A 235/75R15 tire for the 1991 GMC Trucks Jimmy should first match the vehicle's existing 15-inch wheel setup and intended use. In this size, available options range from classic-style whitewall radials to the BFGoodrich All-Terrain T/A KO2, so the choice is not just about size but also tread character, sidewall appearance, and rim-width compatibility.

A road-driven Jimmy with a restoration-minded look may lean toward narrow or wide whitewall radial designs, while a truck used on mixed pavement and dirt may suit the all-terrain pattern. It also helps to compare load figures, wheel-width ranges, and tire weight if the truck carries gear or sees regular use beyond casual cruising.

The 1991 GMC Trucks Jimmy has several sidewall styles available across its applicable tires. In 235/75R15, choices include RWL, narrow whitewall, and wide whitewall, while the 31X10.50R15 all-terrain option uses RWL. That gives the Jimmy a wide visual range, from classic custom-truck styling to a more rugged truck presentation.

Sidewall style can change the personality of the vehicle almost as much as the wheel itself. A whitewall can suit a restoration-oriented or period-inspired build, while raised white letters tend to emphasize utility and off-road flavor. The best choice depends on whether the truck is being kept stock-appearing, customized, or used in a more work-ready and trail-ready way.

Tires for the 1991 GMC Trucks Jimmy are available from BFGoodrich, American Classic, Maxxis, Coker Classic, Tornel, and Travelstar. Most of that variety appears in 235/75R15, where the Jimmy has both classic-looking radials and all-terrain choices. The 31X10.50R15 offering centers on BFGoodrich in an all-terrain radial design.

Brand choice matters most after the correct size is settled. Some options emphasize traditional sidewall styling, while others focus more on truck-oriented tread character. Comparing each tire by series, sidewall treatment, rim-width range, and load rating will tell you more than the brand name alone when deciding what belongs on your Jimmy.

A period-style 1991 GMC Trucks Jimmy usually starts with choosing the correct primary size for the wheel and stance already on the truck, then selecting a radial that supports the look you want. In 235/75R15, the Jimmy has several classic-style whitewall choices as well as more truck-like all-terrain styling, while 31X10.50R15 leans strongly toward a bolder light-truck appearance.

The right visual direction depends on whether the truck is being preserved as a stock-looking driver, given a custom cruiser treatment, or kept in a tougher utility style. When exact originality matters, wheel type, photos, sales literature, and marque-specific references are worth reviewing before choosing a whitewall width or sidewall treatment for the finished look.

Tire construction is less of a visual divide here than it is on older vehicles, because the 1991 GMC Trucks Jimmy uses radial fitments in both primary sizes. The bigger appearance difference comes from the size itself and the sidewall treatment. A 235/75R15 with a whitewall presents very differently from a 31X10.50R15 all-terrain with raised white letters.

That means a restoration-oriented tire decision should focus on proportions and sidewall style rather than a bias-ply-versus-radial question. Matching the tire's look to the wheel design, ride height, and intended era feel will usually have the greatest visual impact. Even a correct-size tire can look out of place if the sidewall treatment does not suit the truck's overall presentation.

Yes, modifications can affect tire fitment on a 1991 GMC Trucks Jimmy even when the wheel still has the correct 15-inch diameter. Changes such as aftermarket wheels, different wheel widths, altered offset, suspension lifts or lowering, and body or steering components in worn condition can all change how a 235/75R15 or 31X10.50R15 tire sits and clears.

A Jimmy that has been changed over the years should be checked at full steering lock and through suspension movement before settling on a new set. The taller and wider 31X10.50R15 deserves especially careful attention. Looking at current tire-to-fender and tire-to-suspension clearance is usually more useful than assuming the truck still matches original dimensions.

Before driving a 1991 GMC Trucks Jimmy on new tires, inspect the wheels for damage, verify the wheel width suits the tire, and confirm that all lug hardware is correct and properly tightened. It also helps to check suspension wear, steering play, brake condition, and whether the tires clear the fenders and chassis components throughout normal steering travel.

A road test should begin with proper inflation and a short drive to catch vibration, rubbing, or pull before heading onto longer trips. Older trucks often hide issues that only show up once fresh tires are installed. Rechecking pressure, lug torque, and visible clearance after the first few miles is a sensible step on a vintage SUV.

Tires on a collector 1991 GMC Trucks Jimmy should be maintained with regular pressure checks, visual inspections, and attention to age-related deterioration. Tread depth matters, but sidewall cracking, bulges, cuts, flat spotting, and slow air loss can matter just as much on a truck that is driven infrequently. That applies whether the Jimmy uses 235/75R15 or 31X10.50R15 tires.

Storage conditions make a real difference on low-use vehicles. Keeping the truck away from prolonged sunlight, excess heat, standing moisture, and ozone sources helps preserve the tires between drives. Moving the vehicle occasionally, checking inflation before each outing, and inspecting the spare as carefully as the road tires are smart habits for dependable vintage-truck use.