The 1946 Buick 70 Roadmaster arrived as Buick re-entered civilian production after World War II, carrying the long, substantial presence buyers expected from a top-line full-size American car of the period. Its broad fenders, generous bodywork, and formal road manners are closely tied to the tall-profile tire look that defines many immediate postwar cars. For this Buick, the primary fitment is a 700-15 bias-ply tire on a 15-inch rim. Available choices include blackwall and wide whitewall presentations across several classic bias-ply series. The real decision is matching the tire's appearance and duty type to the car's restoration goals, wheel setup, and intended driving use.
Which Tire Size Is Right for The 1946 Buick 70 Roadmaster
The 1946 Buick 70 Roadmaster uses one primary tire size: 700-15. That fitment is a bias-ply design built for a 15-inch rim, and it also carries across the covered 8-cylinder Roadmaster sub-model. Since the size itself is straightforward, the main choice becomes selecting the right version within 700-15, including sidewall appearance, tire series, and whether a passenger-car or heavier-duty pattern makes sense for the vehicle you actually have.
A 700-15 is a vintage numeric bias-ply size in which the leading number refers to an approximate 7.00-inch nominal section width and the final number identifies a 15-inch rim. On a 1946 Buick 70 Roadmaster, that keeps the tall, rounded sidewall profile and traditional construction associated with immediate postwar full-size cars. Within this size, choices include Firestone, BFGoodrich, and STA options, with blackwall and wide whitewall styles plus several series aimed at classic or heavier-duty use. Choosing among them comes down to the Buick's intended presentation, wheel compatibility, and whether the car is being restored for appearance or driven in more utility-oriented conditions.
Tire fitment is straightforward across the covered 1946 Buick 70 Roadmaster sub-models. The important step is confirming that the car still retains the expected 15-inch wheel setup, then selecting the 700-15 version that best suits its appearance and use.
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1946 Buick 70 Roadmaster 8 Cyl.
The 1946 Buick 70 Roadmaster 8 Cyl. uses the same 700-15 bias-ply tire size as the core fitment for this model. That keeps tire selection focused on sidewall style, classic passenger-car presentation, or heavier-duty tread choices rather than sorting through multiple primary sizes.
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 1946 Buick 70 Roadmaster Tires for Sale
Available 700-15 options for the 1946 Buick 70 Roadmaster include Firestone, BFGoodrich, and STA bias-ply tires. The product mix gives buyers a choice between blackwall and wide whitewall styling, classic passenger-car series, and several heavier-duty patterns that should be compared carefully against the Buick's intended use.
Common questions for the 1946 Buick 70 Roadmaster usually center on the 700-15 tire size, 15-inch rim fitment, sidewall appearance, product differences, and what to inspect before putting a postwar collector car back on the road.
Tire Size & Fitment
What tire size fits a 1946 Buick 70 Roadmaster?
The 1946 Buick 70 Roadmaster uses a 700-15 tire. This is a numeric bias-ply size paired with a 15-inch rim, and it is the primary fitment for the covered Roadmaster application, including the 8-cylinder sub-model.
That makes the size question fairly simple, but the selection process still matters. A Roadmaster with original-type wheels should be matched to a 700-15 built for the proper rim width, and any car with replacement wheels should have its actual wheel diameter and width checked before a tire is chosen.
What size rim does a 1946 Buick 70 Roadmaster use?
The primary tire fitment for the 1946 Buick 70 Roadmaster is built around a 15-inch rim. Products in 700-15 are matched to that wheel diameter, and several of the available passenger-car options are intended for rims in the 5.00 to 5.50 inch width range.
Wheel diameter should be confirmed before ordering because a postwar car may have been altered over the years. Measuring the wheel and checking its width matters just as much as knowing the tire size, especially if the Buick has replacement steel wheels, aftermarket wheels, or a utility-oriented setup carried over from an earlier owner.
Does the 1946 Buick 70 Roadmaster 8 Cyl. use the same tire size?
Yes. The covered 1946 Buick 70 Roadmaster 8 Cyl. uses the same 700-15 bias-ply tire size as the main Roadmaster fitment. That keeps size selection consistent rather than splitting the car into multiple primary tire fitments.
Even with shared size fitment, the right tire can still vary by presentation and use. A restoration-minded Buick may call for a more traditional sidewall treatment, while a car used more practically may lead an owner toward a different tread style within the same 700-15 size.
Choosing the Right Tire
What should I consider when choosing a 700-15 tire for a 1946 Buick 70 Roadmaster?
Start with the correct 700-15 size and a bias-ply construction that matches the Buick's original-era tire format. From there, compare sidewall style, tire series, rim-width compatibility, and whether the tire is aimed at classic passenger-car appearance or a heavier-duty service pattern.
A Roadmaster restored for period style often points buyers toward a traditional passenger-car bias-ply, especially in wide whitewall form. A car that has been adapted for utility use should be evaluated more carefully so the tread type, load style, and wheel setup make sense for how the vehicle is actually driven.
What sidewall styles are available for 1946 Buick 70 Roadmaster tires?
The 700-15 choices for a 1946 Buick 70 Roadmaster include blackwall and wide whitewall sidewall styles. That gives owners a clear appearance decision, since the sidewall treatment has a major effect on how a large postwar Buick presents visually.
Wide whitewalls generally create a more formal, restoration-oriented look, while blackwalls deliver a plainer and more utilitarian presentation. The best choice depends on the car's finish, trim level of restoration, and whether the goal is a traditional boulevard appearance or a simpler road-use setup within the same fitment.
What brands offer tires for the 1946 Buick 70 Roadmaster?
Tires in the 1946 Buick 70 Roadmaster's 700-15 size are available from Firestone, BFGoodrich, and STA. Those options span classic bias-ply passenger-car offerings as well as several heavier-duty patterns in the same basic size.
Brand alone should not be the only filter. Compare the tire series, sidewall treatment, rim-width guidance, and intended character of the tire so the final choice matches the Buick's appearance and use, rather than simply selecting the first 700-15 option that appears in the correct size.
Restoration & Appearance
Which tire should I choose for a period-style 1946 Buick 70 Roadmaster?
A period-style 1946 Buick 70 Roadmaster starts with the correct 700-15 bias-ply size, since that preserves the tall-profile look and construction style associated with large American cars of the immediate postwar era. Passenger-car bias-ply lines are usually the natural starting point for that type of presentation.
Appearance still depends on details such as sidewall treatment and the overall character of the car. Owners pursuing exact originality should compare the chosen tire against marque references, period photos, or restoration documentation, because a correct size alone does not prove that a particular brand or sidewall treatment matches the car as delivered.
How does tire construction affect the appearance of a restored 1946 Buick 70 Roadmaster?
Tire construction has a major visual effect on a restored 1946 Buick 70 Roadmaster because the car's wheel openings and body proportions were designed around a tall, rounded bias-ply profile. Staying with a 700-15 bias-ply helps preserve the traditional stance and sidewall character expected on a car from this period.
The visual result is only part of the decision, though. Sidewall style, wheel width, and the specific tire series also influence how authentic or understated the finished car appears, so buyers should look at the whole combination rather than treating construction type as the only appearance factor.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1946 Buick 70 Roadmaster?
Yes. Even though the primary fitment is a 700-15 on a 15-inch rim, modifications can change what actually works on a 1946 Buick 70 Roadmaster. Replacement wheels, altered wheel width, suspension changes, brake conversions, or body repairs can all affect how a tire sits and clears.
A Buick that has been changed from its original setup should have its wheel diameter, wheel width, and available clearance checked before a new set is chosen. Steering sweep, fender clearance, and the condition of springs and suspension components also matter, especially on a large collector car that may have settled over time.
What should I inspect before driving a 1946 Buick 70 Roadmaster on new tires?
Before driving a 1946 Buick 70 Roadmaster on new tires, inspect the wheels, valve hardware, and overall wheel condition, then confirm proper mounting and inflation. It is also wise to check brake operation, steering response, and whether the tires clear the fenders and suspension through a full range of movement.
A postwar Buick often spends long periods parked, so road readiness involves more than fresh rubber. Look over the suspension for looseness, examine the alignment if the car tracks poorly, and make sure there are no signs of rubbing after the first short drive and recheck.
How should 700-15 tires on a collector 1946 Buick 70 Roadmaster be maintained?
Collector-car 700-15 tires should be maintained with regular pressure checks, visual inspections, and careful storage habits. On a 1946 Buick 70 Roadmaster, that means watching for sidewall cracking, cuts, bulges, uneven wear, and slow air loss, even if the car is driven only occasionally.
Long idle periods can age tires without adding many miles, so condition matters as much as tread depth. Keeping the Buick away from prolonged sunlight, excess heat, and ozone sources helps preserve the rubber, and periodic inspection remains important before local drives as well as longer touring use.
