1968 Ford Thunderbird Tires

A 1968 Ford Thunderbird uses one of four bias-ply tire sizes: 8.45-15, 855-15, 8.25-15, or 815-15. The correct size depends on the exact sub-model. All Other Models use 8.45-15 or 855-15, while Tudor Non-Air uses 8.25-15 or 815-15.

That means the first step is identifying the car’s specific configuration before choosing a tire. Even though all four sizes mount on 15-inch rims, they are not simply interchangeable by assumption. Once the right primary size is confirmed, the next decisions are sidewall style, restoration appearance, and whether a radial equivalent is being considered for an 855-15 application.

The covered tire fitments for the 1968 Ford Thunderbird use a 15-inch rim diameter. That applies across 8.45-15, 855-15, 8.25-15, and 815-15, so the wheel diameter remains consistent even though the tire sizes vary by sub-model.

Rim diameter is only part of the fitment picture, so it helps to confirm wheel width as well before selecting a tire. Product specifications for the available bias-ply options show different rim-width ranges depending on size. If the car has replacement wheels, checking both wheel dimensions and sub-model-specific sizing will prevent confusion between the Thunderbird’s several 15-inch tire choices.

The 1968 Ford Thunderbird has more than one tire size because fitment changes between covered sub-models. All Other Models use 8.45-15 or 855-15, while Tudor Non-Air uses 8.25-15 or 815-15. All of them are bias-ply sizes on 15-inch rims, but they are not assigned uniformly across the line.

For a buyer, that means tire selection starts with the exact Thunderbird configuration rather than the model name alone. It also means appearance choices and radial-equivalent planning may differ depending on the original size. Confirming the wheel already on the car is worthwhile too, especially if it has been modified or if the existing tires are not a reliable guide to proper fitment.

For the 1968 Ford Thunderbird, 855-15 is a primary bias-ply tire size. It belongs to the vintage numeric bias-ply system and is one of the covered fitments used on 15-inch rims. The available product choices in this size are bias-ply tires rather than primary radial fitments.

That distinction matters because a radial equivalent serves as an alternative approach, not the original construction style. Buyers trying to preserve a traditional driving presentation or period-style appearance often stay with bias-ply, while others may compare radial options separately. Any change in construction should be checked against wheel width, vehicle clearance, and the overall setup already on the Thunderbird.

Radial equivalents for 855-15 include 215R15, P225/75R15, P235/70R15, and 760R15. Those cover an 80-series metric radial, a 75-series P-metric radial, a 70-series P-metric radial, and a bias-look radial equivalent. The recommended rim-width range for these equivalents is 6 to 8 inches.

Each option represents a different sizing convention and, in the case of 760R15, a different visual approach as well. A buyer considering one of these alternatives should compare the actual wheel width, confirm 15-inch wheel diameter, and check clearance at the fenders and steering range. Equivalent sizing is useful guidance, but it still needs to be matched to the car’s present wheel and suspension setup.

Start by confirming which original bias-ply size the 1968 Ford Thunderbird uses, because only 855-15 has a defined set of radial equivalents here. Then verify the wheel diameter and width, since the radial equivalents for 855-15 carry a recommended rim-width range of 6 to 8 inches.

Construction changes should also be evaluated against the car’s actual clearance and condition, not just the nominal size on paper. Check front steering travel, fender room, suspension wear, and whether the car still has its original wheels. That extra verification helps ensure the chosen radial alternative suits the Thunderbird’s current setup rather than assuming every equivalent size behaves the same.

Choosing a 855-15 tire for a 1968 Ford Thunderbird starts with confirming that your sub-model actually uses that size. Once that is established, the decision becomes one of construction strategy and appearance, since 855-15 is available as a bias-ply product and also has defined radial-equivalent alternatives.

Within the available bias-ply products, compare sidewall treatment, rim-width specification, and load information such as 1710@32 psi. The BFGoodrich options in this size share the Silvertown Classic Bias Ply series but differ in whitewall presentation. That makes 855-15 a good example of how proper fitment comes first, with styling and use goals shaping the final selection.

Available sidewall styles for 1968 Ford Thunderbird tires include Narrow Whitewall and Whitewall-Redline. The narrow whitewall appears in both 855-15 and 815-15 offerings, while the whitewall-redline treatment appears in 815-15. These options stay within a traditional bias-ply presentation rather than shifting the car into a modern tire look.

Sidewall choice influences the Thunderbird’s finished appearance as much as the tire size itself, especially on a large personal luxury car with strong body-side visual lines. It still makes sense to settle the correct sub-model fitment first, then choose the sidewall that matches the car’s restoration direction, trim presentation, and intended use rather than selecting purely by style.

The available products for the covered 1968 Ford Thunderbird sizes shown here are in the BFGoodrich Silvertown Classic Bias Ply series. That series appears in both 855-15 and 815-15, keeping the focus on traditional bias-ply construction and vintage-style sidewall presentation rather than offering several unrelated modern tire lines.

Because the series stays consistent, most of the decision shifts to size, sidewall style, and wheel compatibility. Buyers comparing options should look at the exact tire size for the sub-model, the stated rim-width range, and visual details such as narrow whitewall versus whitewall-redline. That approach keeps the selection grounded in fitment first, with appearance choices following naturally.

A period-style 1968 Ford Thunderbird should begin with the correct bias-ply size for the exact sub-model: 8.45-15 or 855-15 for All Other Models, and 8.25-15 or 815-15 for Tudor Non-Air. Staying within the original-style bias-ply format preserves the visual character that suits a late-1960s Thunderbird’s stance and proportions.

After size is settled, sidewall treatment becomes the main appearance decision among the available products. Narrow whitewall options are offered, and 815-15 also has a whitewall-redline choice. For buyers pursuing exact historical authenticity beyond a period-style approach, marque references, build records, and model-specific restoration guidance remain the best way to confirm the most appropriate presentation.

Tire construction has a visible effect on a restored 1968 Ford Thunderbird because bias-ply tires present the car in a more traditional late-1960s style. All primary fitments for this Thunderbird are bias-ply, so keeping that construction maintains the look associated with the original sizing format and sidewall proportions.

A radial alternative can change the visual impression even when it remains close in intent to the original size, particularly if the sizing format moves into metric or P-metric territory. That does not make a radial wrong, but it does make the choice more than a technical one. For restoration-oriented owners, appearance goals should be weighed alongside fitment checks and planned road use.

Yes, modifications can affect tire fitment on a 1968 Ford Thunderbird even when the nominal tire size matches one of the original-style options. Changes to wheels, suspension height, springs, or body clearance can alter how an 8.45-15, 855-15, 8.25-15, or 815-15 tire sits and moves through steering travel.

That is especially important on a car with multiple correct sizes by sub-model, because an aftermarket setup may no longer reflect the original wheel dimensions. Checking wheel width, wheel diameter, and clearance at the front and rear helps prevent selecting a tire by memory or by what is already mounted. A modified Thunderbird should always be measured against its current configuration.

Before driving a 1968 Ford Thunderbird on new tires, inspect the wheels for correct diameter and condition, confirm the tire size matches the sub-model, and make sure inflation is set appropriately for the tire being used. It is also smart to check for any visible interference at the fenders, suspension, and full steering lock.

A collector-era car often needs more than a quick tread glance before returning to the road. Look over the suspension, alignment condition, and any signs that the old tires wore unevenly. A short, careful initial drive can reveal rubbing, pulling, or vibration before the car is taken farther, which is especially helpful when a long-stored Thunderbird is back in service.

855-15 tires on a collector 1968 Ford Thunderbird should be maintained with regular pressure checks, visual inspections, and periodic review of tread and sidewall condition. Because collector cars are often driven infrequently, it is important to look for aging signs such as cracking, bulges, cuts, or recurring air loss rather than judging condition by mileage alone.

Storage practices matter nearly as much as road use on a low-mile Thunderbird. Keeping the car away from prolonged heat, direct sunlight, moisture, and ozone sources helps preserve the tires over time. It also pays to recheck the wheel and tire setup before longer drives, particularly if the car has sat for extended periods or has changed hands recently.