1981 BMW Tire Fitment Guide

1981 BMW vehicles use four tire sizes, divided by model. The 320i uses 185/70R13, the 528i uses 185/70R14, and the 633CSi and 733i use either 205/70R14 or 220/55R390 depending on wheel type. The first three sizes fit 13-inch or 14-inch conventional wheels, while 220/55R390 fits a 390mm metric TRX wheel. Rim width support also varies by size and product, with examples ranging from 4.5-6.0 inches on some 185-section tires to 5.5-7.5 inches on some 205/70R14 tires.

That spread means a 1981 BMW owner should identify the exact model before doing anything else, then confirm the actual wheel diameter on the car. This is especially important on the 633CSi and 733i, where a standard 14-inch tire and a TRX metric tire are not interchangeable. Once the model and wheel format are confirmed, the remaining decisions are mostly about sidewall style, brand preference, and how closely you want the tire to match the car’s intended look and use.

On a 1981 BMW, 185/70R13 is a metric radial size. The 185 is the nominal section width in millimeters, 70 is the aspect ratio, R means radial construction, and 13 is the wheel diameter in inches. In this year and make, that size belongs to the 320i. Available versions include blackwall, redline, and wide whitewall sidewalls, with some products carrying H or V speed ratings depending on the exact tire.

That code matters because it identifies both the physical fitment and the character of the tire options available to a 320i owner. A blackwall performance-oriented radial gives a different visual impression than a redline or wide whitewall, even when the basic size is the same. If your car has been modified over the years, verify that the wheel is still 13 inches before assuming the original metric radial code remains correct.

On a 1981 BMW, 220/55R390 is a metric radial TRX size rather than a conventional inch-based tire size. The 220 is the nominal width in millimeters, 55 is the aspect ratio, R identifies radial construction, and 390 is the wheel diameter in millimeters. In 1981 BMW applications, this size belongs to the 633CSi and 733i when they are equipped with TRX wheels. Michelin offers this size as a blackwall tubeless tire with a W speed rating, which carries a 168 mph ceiling.

The key practical point is that 390mm TRX wheels do not accept ordinary 14-inch tires, even though the numbers may seem close at a glance. Owners of a 633CSi or 733i should inspect the wheels themselves and confirm whether the car still has the TRX system or has been converted to conventional wheels. That one check prevents the most common ordering mistake on early-1980s BMW grand touring and luxury models.

No, 1981 BMW models do not use one universal tire size. The 320i uses 185/70R13, the 528i uses 185/70R14, and the 633CSi and 733i use either 205/70R14 or 220/55R390. Even where two models share the same size options, as the 633CSi and 733i do, the tire still depends on the wheel system fitted to the car. Every size in this year-make group is radial, but the diameters and wheel standards are not the same.

That means the safe starting point is always model identification, followed by wheel verification if you own one of the larger BMWs. A 528i owner can narrow the search quickly because only one 14-inch size applies, while a 633CSi or 733i owner needs to determine whether the car remains on TRX wheels or conventional inch-diameter wheels. Once that is settled, the choice becomes much more straightforward.

1981 BMW tire choices span a wider range of sidewall styles than many owners expect. Blackwall options appear across all four sizes, while 185/70R13 also comes in redline and wide whitewall, 185/70R14 appears in blackwall and wide whitewall, and 205/70R14 can be found in narrow whitewall, RWL, redline, and dual redline versions. The TRX size, 220/55R390, is available as a blackwall tire. That means sidewall appearance changes not only by taste, but also by the exact size your model uses.

For a 1981 BMW restored with European-market flavor in mind, blackwall is usually the most era-consistent visual direction. Whitewall, redline, and raised white letter styles can still appeal to owners building a period-custom or market-specific look, especially on U.S.-focused collector cars. The important thing is to choose the sidewall treatment after confirming the correct size, because the full range of appearances is not available in every fitment.

1981 BMW vehicles are covered by BFGoodrich, Avon, Dunlop, Michelin, and Maxxis, depending on size. The 185/70R13 is available from BFGoodrich, Avon, and Dunlop; the 185/70R14 from BFGoodrich, Avon, Dunlop, and Michelin; the 205/70R14 from Maxxis and BFGoodrich; and the 220/55R390 from Michelin. Brand choice therefore depends heavily on model and wheel format rather than year and make alone. Every option in this group uses radial construction.

That brand spread gives owners room to prioritize different goals within the correct fitment, whether that means a more European-looking blackwall presentation, a heritage-style sidewall treatment, or a tire tied to the TRX system itself. If you are comparing products, start by narrowing the search to the exact size on your car and then compare speed rating, sidewall style, and wheel-width compatibility. Brand comes after fitment, not before it.

For 1981 BMW applications in 205/70R14, BFGoodrich Radial T/A and BFGoodrich Silvertown Radial differ mainly in sidewall presentation, speed marking, and wheel-width range. The Radial T/A uses an RWL sidewall, carries a 93S marking with a 112 mph speed ceiling, and fits a 5.00-7.00 inch rim range. The Silvertown Radial appears in redline and dual redline form, and those versions fit a 5.50-7.50 inch rim range. Load capacity on both families in this size reaches 1,433 pounds at 35 psi where stated.

That makes the choice less about one tire being universally better and more about matching the car’s look and wheel setup. An owner after a sportier raised-letter appearance may gravitate toward the Radial T/A, while a more heritage-styled build may lean toward the Silvertown redline versions. Before deciding, confirm the wheel width on the car so the selected tire falls within the recommended range for that exact product.

Rim width requirements for 1981 BMW tires vary by size and sometimes by product within the same size. In 185/70R13, examples include 4.5-6.0 inches and 5.00-6.50 inches. In 185/70R14, examples include 4.50-6.00 inches and 5.00-6.50 inches. In 205/70R14, wheel-width support runs from 5.00-7.00 inches on some products to 5.50-7.50 inches on others, while 220/55R390 TRX tires fit metric wheel widths of 135mm, 150mm, and 180mm.

Those ranges show why size alone is not the final step in fitment. Two tires with the same nominal size can have different approved wheel-width ranges, so the wheel on the car should be measured or confirmed before choosing a specific product. That is especially important on the 205/70R14 fitment, where some products start at a wider minimum wheel than others, and on TRX-equipped cars, where the wheel standard is metric from the outset.

Most 1981 BMW tire options here are radial products without an explicit tube-type marking, and the 220/55R390 Michelin TRX-B is clearly marked TL for tubeless use. Some 185/70R14 products also carry a tubeless marking, while others in the same size do not show one in the sidewall code. That means tube status can vary by product presentation rather than by year and make alone. No size in this group should be assumed tube-type without checking the exact tire and wheel combination.

The practical takeaway is to match the tire to the wheel condition and design, not simply to the size code. Original alloy and steel wheels in good tubeless-ready condition are often run without tubes when the tire is marked accordingly, but an older wheel with corrosion, damage, or an unusual sealing surface deserves closer attention. If you are preserving original wheels, it is wise to verify the tire’s sidewall marking and confirm the wheel’s suitability during mounting.

A 1981 BMW should be stored in a cool, dry, dark space away from direct sunlight, electric motors, battery chargers, furnaces, and other ozone-producing equipment. Tire pressures should be kept up during storage, and the car should be moved periodically so it does not sit on one contact patch for months at a time. Radial tires generally tolerate storage better than older bias-ply designs, but they still age from heat, ozone, and long static loads.

Owners who store a BMW for winter or for long intervals between shows often benefit from rolling the car occasionally or using stands in a way that does not stress suspension pickup points. Cleaning road salts and brake dust from the wheels and sidewalls before storage also helps preserve appearance. If the car rides on TRX tires, storage discipline matters even more because replacement choices are naturally narrower than on conventional 13- and 14-inch fitments.

On a 1981 BMW collector car, tire age usually matters more than tread depth. A sound rule is to evaluate tires closely once they reach the five- to seven-year range and to treat ten years as a serious replacement point regardless of mileage. Heat cycles, storage conditions, underinflation, and long periods of inactivity all affect service life. The DOT date code on the sidewall is the reference point for age, not the date the car was restored or acquired.

That age-based approach is especially important on cars that see short seasonal drives and accumulate very little wear. A tire can still look respectable from a few feet away yet have internal age-related hardening, cracking, or weakened adhesion. When a 1981 BMW is driven infrequently, build your maintenance schedule around calendar age and inspection results rather than waiting for the tread to look worn out.

Tires on a 1981 BMW should be inspected before every drive and again before any longer outing. Look for sidewall cracking, cuts, bulges, uneven wear, punctures, and pressure loss, and check that the valve stems remain pliable and secure. Wheels should also be examined for damage or corrosion at the bead area. On TRX-equipped cars, confirming that all four tires match in size and type is particularly important.

A quick walkaround catches many problems before they become roadside issues, especially on older cars that may sit for extended periods. For longer drives, include the spare in the inspection routine and make sure it is still serviceable, not simply present. Regular checks also help reveal alignment or suspension wear early, since unusual tread wear patterns often show up in the tire before they are obvious elsewhere.

A 1981 BMW 320i was originally part of an era when radial construction was already established on European passenger cars, and the correct fitment family here is 185/70R13. That size aligns with the 320i’s compact sport-sedan role and 13-inch wheel fitment. Original-equipment branding could vary by market and delivery specification, so size and construction are the safest authenticity anchors unless a car’s paperwork or surviving factory literature points to something more specific.

For restoration work, the most important first step is preserving the correct 185/70R13 radial size and then choosing the sidewall style that best matches your car’s intended presentation. A blackwall treatment is usually the most natural visual fit for a European 1981 BMW, while redline or whitewall selections can push the car toward a different period look. If the goal is judged originality, consult BMW marque clubs or factory literature for market-specific guidance.

Correct tire fitment absolutely matters when showing a 1981 BMW, especially in events that value factory-correct appearance and period consistency. Judges and knowledgeable enthusiasts notice size, construction, wheel standard, and sidewall style. A 633CSi or 733i wearing TRX wheels should have the proper metric-size TRX tire, while a car restored around conventional 14-inch wheels should wear the corresponding inch-based size. An obviously mismatched sidewall treatment can also stand out on a carefully restored BMW.

The level of scrutiny depends on the event. A local casual show may reward overall presentation, while marque judging often pays attention to whether the tire visually suits the exact model and era. If authenticity is your priority, treat the wheel-and-tire combination as one restoration decision rather than two separate ones. BMW club resources and period brochures are especially useful when the car falls into the gray area between U.S.-market tastes and European-delivery correctness.

For a 1981 BMW 633CSi or 733i, Michelin TRX-B in 220/55R390 and a conventional 205/70R14 tire differ first in wheel system, not just in size. The TRX-B fits a 390mm metric wheel and carries a W speed rating with a 168 mph ceiling, while 205/70R14 fits a standard 14-inch wheel and appears in several visual styles from different brands, including at least one S-rated version with a 112 mph ceiling. They are not interchangeable on the same wheel.

From an authenticity standpoint, the TRX setup matters because it was a distinct period technology and a recognizable part of some upper-range BMW specifications. Conventional 14-inch tires offer more visual variety and a more familiar wheel format, but they belong only on cars equipped with the corresponding wheels. If your goal is to preserve how the car was configured when new, verify whether it originally carried TRX equipment before choosing between the two paths.

1981 BMW tires can be appropriate for highway driving when the correct size is matched to the correct wheel and the tire is in sound condition. Speed ratings vary by product: some 185/70R13 and 185/70R14 options carry H or V ratings with 130 mph and 149 mph ceilings, 205/70R14 includes at least one S-rated product with a 112 mph ceiling, and the 220/55R390 TRX tire carries a W rating to 168 mph. Those ratings exceed normal U.S. highway speeds, but age and condition still matter more than the printed ceiling.

A healthy tire is only one part of the equation on a 1981 BMW. Suspension bushings, alignment, brakes, wheel bearings, and the overall condition of the car may become the limiting factors before the tire’s speed rating does. For regular road use, focus on proper inflation, recent inspection, and a tire whose age is appropriate for service, rather than assuming any old tire is safe simply because it once had a high speed rating.

Inflation pressure on a 1981 BMW should follow the vehicle’s factory recommendations first, with the tire manufacturer’s ratings used as the upper reference for that specific product. Several tires here also show their load-and-pressure relationship: 185/70R13 examples reach 1,135 pounds at 35 psi, 185/70R14 examples reach 1,201 pounds at 35 psi or 1,235 pounds where marked, and multiple 205/70R14 products reach 1,433 pounds at 35 psi. Those figures describe the tire’s capacity at stated pressure, not the blanket pressure every BMW should run.

That distinction matters because a compact 320i, a 528i sedan, and a 733i luxury sedan do not all place the same demands on the tire. The best practice is to start with the factory pressure specification for your exact model and adjust only within the tire maker’s approved limits if needed for load, ride, or handling balance. Never transfer a pressure figure from one size or model to another just because the sidewall numbers look similar.

Before a longer drive in a 1981 BMW, inspect each tire for cracks, cuts, bulges, punctures, and uneven wear, and verify cold inflation pressure on all four corners plus the spare. Check valve stems, wheel condition, and lug torque, and make sure all tires match the wheel system on the car—especially if it is a 633CSi or 733i that could be on TRX or conventional wheels. A tire that has aged out or begun separating should be replaced before the trip, regardless of remaining tread.

That tire inspection should be part of a wider pre-trip routine that also covers brakes, belts, hoses, fluids, lights, and charging-system health. Older BMWs are rewarding road cars when sorted, but they respond best to careful preparation rather than last-minute assumptions. Spending a few minutes on the tires before departure often reveals small issues early, when they are still easy to correct at home instead of on the shoulder.