The 1968 Oldsmobile 88 Series sits in the full-size American car era when ride quality, road presence, and generous proportions shaped the driving experience as much as styling did. For owners restoring or maintaining one today, tire choice has a real effect on both appearance and stance. The 1968 Oldsmobile 88 Series uses bias-ply fitments in four primary sizes: 855-14, 855-15, H78-14, and H78-15. Those sizes open up different period-style looks, including narrow whitewall, wide whitewall, and blackwall options, while modern radial equivalents are also available for owners considering an alternate construction. The key is matching the correct size and wheel diameter before deciding how original or road-oriented the finished setup should be.
Which Tire Size Is Right for The 1968 Oldsmobile 88 Series
The 1968 Oldsmobile 88 Series uses four primary tire sizes, and the first step is confirming both the exact wheel diameter and the size already fitted to the car. These fitments are all bias-ply, but they span both 14-inch and 15-inch rims, so a buyer should verify the actual wheel setup before choosing among the available period-style tires or evaluating modern radial equivalents.
An 855-14 is a numeric bias-ply size in which the 8.55 designation refers to the tire's nominal section width in inches, and the final 14 indicates a 14-inch rim. For the 1968 Oldsmobile 88 Series, it represents a traditional full-size car fitment with the look and construction many restoration-minded owners want to keep. Available choices in this size come from BFGoodrich in the Silvertown Classic Bias Ply series with narrow whitewall treatments. It is a useful size to consider when maintaining a stock-style 14-inch wheel setup and a classic sidewall presentation.
An 855-15 follows the same numeric bias-ply sizing system, with 8.55 as the nominal section width and 15 as the rim diameter in inches. On a 1968 Oldsmobile 88 Series, this size keeps the original-style bias-ply construction while shifting the fitment to a 15-inch wheel. BFGoodrich offers this size in the Silvertown Classic Bias Ply line with narrow whitewall versions, giving buyers a traditional appearance choice within the correct fitment family. It makes the most sense after confirming that the car is actually running 15-inch wheels rather than a 14-inch setup.
H78-14 is a vintage alphanumeric bias-ply size, where the letter and series identify the tire's size class and profile family, while the 14 marks the rim diameter. For the 1968 Oldsmobile 88 Series, it is another period-correct style of bias-ply fitment for a 14-inch wheel, but with a different sizing convention than the older numeric format. In this size, the available choice is a Coker Classic Bias Ply with a wide whitewall, giving the car a noticeably different visual character. It is best suited to owners aiming for a broad whitewall look on a confirmed 14-inch wheel package.
H78-15 uses the same vintage alphanumeric bias-ply system, with the H78 designation describing the tire's size class and profile group and the 15 showing the required rim diameter. On the 1968 Oldsmobile 88 Series, this fitment supports a 15-inch wheel and offers the broadest visible choice in appearance. Options include Coker Classic Bias Ply wide whitewalls and an STA Traxion blackwall in the Traxion series. This size is worth close attention when the goal is to match a specific visual style, especially on a car already set up with 15-inch wheels.
The covered 1968 Oldsmobile 88 Series Base configuration can use more than one primary tire size, so the important step is not trim identification so much as confirming the wheel diameter and tire format already on the car. That matters because both numeric and alphanumeric bias-ply sizes appear here across 14-inch and 15-inch rims.
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1968 Oldsmobile 88 Series Base
The 1968 Oldsmobile 88 Series Base uses all four primary bias-ply fitments found on this page, so selection starts with the actual wheel diameter and size family on the vehicle. Once that is confirmed, the choice shifts to appearance details such as narrow whitewall, wide whitewall, or blackwall, along with any radial-equivalent plans.
Bias-Ply to Radial Tire Conversion for the 1968 Oldsmobile 88 Series
The 1968 Oldsmobile 88 Series has radial-equivalent options for all four primary bias-ply sizes. For 855-14 and H78-14, the equivalents are 215R14 as an 80-series metric radial, P225/75R14 as a 75-series P-metric radial, and P235/70R14 as a 70-series P-metric radial. For 855-15 and H78-15, the equivalents are 215R15, P225/75R15, P235/70R15, plus 760R15 as a bias-look radial. Recommended rim-width ranges are 5-7 for the 14-inch equivalents and 6-8 for the 15-inch equivalents, and wheel width plus vehicle clearance should be checked before changing construction.
Modern Radial Equivalents
215R14
Equivalent 80-series Metric Radial (855-14)
P225/75R14
Equivalent P-metric 75-series Radial (855-14)
P235/70R14
Equivalent P-metric 70-series Radial (855-14)
215R15
Equivalent 80-series Metric Radial (855-15)
P225/75R15
Equivalent P-metric 75-series Radial (855-15)
P235/70R15
Equivalent P-metric 70-series Radial (855-15)
760R15
Bias-look Radial Equivalent (855-15)
215R14
Equivalent 80-series Metric Radial (H78-14)
P225/75R14
Equivalent P-metric 75-series Radial (H78-14)
P235/70R14
Equivalent P-metric 70-series Radial (H78-14)
215R15
Equivalent 80-series Metric Radial (H78-15)
P225/75R15
Equivalent P-metric 75-series Radial (H78-15)
P235/70R15
Equivalent P-metric 70-series Radial (H78-15)
760R15
Bias-look Radial Equivalent (H78-15)
Important Considerations When Replacing Bias Ply With Radial
Compare overall diameter and section width carefully to ensure proper fit.
Verify recommended rim range (6-8 in) and load needs match your vehicle specifications.
Check fender clearance, steering clearance, and stance before installation.
Consider suspension condition and intended road use when choosing equivalents.
Important Fitment Notes
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 1968 Oldsmobile 88 Series Tires for Sale
Available 1968 Oldsmobile 88 Series tires center on bias-ply choices from BFGoodrich, Coker Classic, and STA. Buyers can compare Silvertown Classic Bias Ply, Coker Classic Bias Ply, and Traxion options across narrow whitewall, wide whitewall, and blackwall sidewall styles.
Common 1968 Oldsmobile 88 Series tire questions usually come down to confirming the correct size and wheel diameter, understanding bias-ply versus radial-equivalent choices, and selecting the right sidewall style for the car's intended look and road use.
Tire Size & Fitment
What tire size fits a 1968 Oldsmobile 88 Series?
The 1968 Oldsmobile 88 Series uses four primary bias-ply tire sizes: 855-14, 855-15, H78-14, and H78-15. Those sizes cover both numeric and alphanumeric vintage sizing formats, and they are split between 14-inch and 15-inch rims rather than one universal wheel diameter.
That means the correct choice starts with the actual wheels on the car, not just the model name. A buyer should confirm whether the Oldsmobile is wearing 14-inch or 15-inch rims and whether the existing fitment follows the 855 numeric format or the H78 alphanumeric format before choosing a replacement tire.
What size rim does a 1968 Oldsmobile 88 Series use?
A 1968 Oldsmobile 88 Series can use either a 14-inch or 15-inch rim, depending on which primary tire size is on the car. The 855-14 and H78-14 sizes use 14-inch rims, while 855-15 and H78-15 use 15-inch rims.
Wheel diameter is the first thing to verify because the tire sizes on this vehicle are not all built around the same rim. Checking the stamp on the wheel, measuring the wheel correctly, or confirming the current tire size on the car helps prevent choosing the right-looking tire in the wrong diameter.
Does the 1968 Oldsmobile 88 Series Base use the same tire size?
The 1968 Oldsmobile 88 Series Base does not narrow the fitment to one single tire size. It can use 855-14, 855-15, H78-14, or H78-15, all in bias-ply construction, so the deciding factor is the wheel and tire setup actually on the vehicle.
That makes the Base model more of a wheel-confirmation question than a trim question. Looking at the current tire markings and confirming whether the car has 14-inch or 15-inch rims will point you toward the correct replacement size and help you choose between narrow whitewall, wide whitewall, or blackwall options.
Bias-Ply & Radial Options
Is 855-14 a bias-ply or radial tire for the 1968 Oldsmobile 88 Series?
For the 1968 Oldsmobile 88 Series, 855-14 is a primary bias-ply tire size. It uses the older numeric sizing format, and on this car it belongs to a 14-inch rim application rather than a modern radial fitment designation.
Keeping 855-14 in bias-ply form preserves the original-style construction and sidewall character associated with vintage full-size cars. A radial alternative can still be considered, but the choice should be checked against wheel width, overall fit on the car, and the owner's goals for ride feel, appearance, and restoration direction.
What radial tire sizes are equivalent to H78-15 on a 1968 Oldsmobile 88 Series?
Radial equivalents for H78-15 on a 1968 Oldsmobile 88 Series include 215R15 as an 80-series metric radial, P225/75R15 as a 75-series P-metric radial, and P235/70R15 as a 70-series P-metric radial. A 760R15 bias-look radial is also available as an alternative in the same general fitment family.
Those choices give different sizing formats and a different visual approach, especially with the bias-look radial option. The recommended rim-width range for these 15-inch equivalents is 6-8 inches, and any change from bias-ply to radial should be checked against the car's wheel width, steering clearance, and overall stance.
What should I check before converting my 1968 Oldsmobile 88 Series from bias-ply to radial tires?
A conversion from bias-ply to radial on a 1968 Oldsmobile 88 Series starts with matching the equivalent size to the car's actual wheel diameter. The next checks are wheel width, tire-to-fender clearance, steering clearance, and whether the chosen radial alternative suits the car's current suspension and ride-height setup.
Construction changes can also affect the way the car looks and feels, even when the size relationship is appropriate. Owners should confirm the condition of the wheels, compare the selected equivalent carefully, and avoid assuming that a radial equivalent is automatically interchangeable simply because it shares the same general fitment category.
Choosing the Right Tire
What should I consider when choosing a 1968 Oldsmobile 88 Series tire?
Start with the correct primary size and the correct rim diameter, because the 1968 Oldsmobile 88 Series uses both 14-inch and 15-inch fitments in two vintage sizing systems. After that, the main considerations are whether to stay with bias-ply construction and which sidewall style best matches the car's intended look.
Product differences also matter once size is settled. Some choices focus on narrow whitewall styling, others on wide whitewall presentation, and H78-15 also introduces a blackwall option. Comparing series, rim-width compatibility, load figures, and how the car will actually be driven helps narrow the right tire for the setup.
What sidewall styles are available for 1968 Oldsmobile 88 Series tires?
The available sidewall styles for the 1968 Oldsmobile 88 Series include narrow whitewall, wide whitewall, and blackwall. The narrow whitewall choices appear in the BFGoodrich Silvertown Classic Bias Ply line, while the H78 sizes bring wide whitewall options from Coker Classic and a blackwall STA Traxion in H78-15.
That variety gives the car very different visual personalities even before construction changes are considered. A buyer should begin with the correct size and wheel diameter, then choose the sidewall treatment that best matches the vehicle's restoration direction, stance, and trim presentation rather than selecting by appearance alone.
What brands offer tires for the 1968 Oldsmobile 88 Series?
BFGoodrich, Coker Classic, and STA all offer tires for the 1968 Oldsmobile 88 Series across the covered fitment range. BFGoodrich appears in the 855 numeric sizes, Coker Classic covers the H78 whitewall choices, and STA provides a blackwall Traxion option in H78-15.
Brand choice should follow fitment, not replace it. Once the correct size and rim diameter are confirmed, compare each brand's available series, sidewall style, rim-width specification, and load capacity details to make sure the tire matches the car's visual goal and the practical demands of how it will be used.
Restoration & Appearance
Which tire should I choose for a period-style 1968 Oldsmobile 88 Series?
A period-style 1968 Oldsmobile 88 Series starts with one of its correct primary bias-ply sizes: 855-14, 855-15, H78-14, or H78-15, depending on wheel diameter and the setup already on the car. From there, the visual character shifts through narrow whitewall, wide whitewall, or blackwall presentations.
The best choice depends on how closely the car is being restored and which wheel package it actually carries. Owners pursuing exact originality should compare the tire style against marque references, historic photos, or build-specific documentation, while others may simply choose the correct size with the appearance that best suits the restoration.
How does tire construction affect the appearance of a restored 1968 Oldsmobile 88 Series?
On a restored 1968 Oldsmobile 88 Series, bias-ply construction usually delivers the most traditional visual character because the car's primary fitments are all bias-ply sizes. That makes construction part of the restoration look, not just a driving decision, especially when paired with narrow or wide whitewall sidewall treatments.
A radial equivalent may still be appropriate for some owners, but it can change the overall presentation even when the wheel diameter stays the same. Anyone balancing road use with restoration appearance should look at both the construction type and the sidewall style together rather than treating them as separate choices.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1968 Oldsmobile 88 Series?
Yes, modifications can affect tire fitment on a 1968 Oldsmobile 88 Series even when the tire size itself is correct for the model. Aftermarket wheels, changes in wheel width, altered ride height, suspension work, or body modifications can all influence clearance around the fenders and steering components.
That matters even more on a car with both 14-inch and 15-inch fitment families available. A buyer should confirm the actual wheel diameter and width on the vehicle, then inspect clearance at full steering lock and through suspension movement before assuming that a size associated with the 88 Series suits a modified example.
What should I inspect before driving a 1968 Oldsmobile 88 Series on new tires?
Before driving a 1968 Oldsmobile 88 Series on new tires, inspect the wheels for condition, confirm the tire size matches the wheel diameter, and verify proper inflation for the selected tire. It also helps to check lug hardware, valve stems, and basic tire-to-body and tire-to-suspension clearance once the tires are mounted.
A short, careful road test is the practical next step. Listen for rubbing, watch for steering pull or vibration, and recheck air pressure after the initial drive. On a collector car, it is also wise to inspect suspension wear and alignment condition so the new tires are not compromised by older chassis issues.
How should 855-14 tires on a collector 1968 Oldsmobile 88 Series be maintained?
855-14 tires on a collector 1968 Oldsmobile 88 Series should be kept properly inflated, inspected regularly for cracking, cuts, bulges, uneven wear, and slow air loss, and stored away from prolonged sun, heat, moisture, and ozone exposure when the car is not used often. Low-mileage collector use does not stop tires from aging.
Routine visual checks matter because vintage cars can sit for long periods between drives. It is smart to inspect the sidewalls and tread before each outing, keep the car on a clean, dry surface, and have any questionable tire or wheel condition evaluated by a qualified tire professional before returning the Oldsmobile to regular road use.
