The 1981 BMW 733i belongs to the first-generation 7 Series, a sedan that helped establish BMW’s large-car formula around high-speed touring, precise road manners, and understated executive styling. Buyers looking at one today are often balancing originality against practical road use, especially because this car could be found with two very different radial tire fitments. A 1981 BMW 733i uses either 205/70R14 or 220/55R390 radial tires, and the choice matters because the second size is the millimetric Michelin TRX format. Available options range from traditional whitewall and blackwall presentations to redline, dual-redline, and raised white letter styles, so wheel type, appearance goals, and true wheel diameter should be confirmed before selecting tires.
Which Tire Size Is Right for The 1981 BMW 733i
The 1981 BMW 733i uses two primary tire sizes, and choosing correctly starts with confirming which wheels are on the car. One fitment is a conventional 14-inch metric radial, while the other is the millimetric 220/55R390 TRX radial, so the real decision is tied to wheel type first and then to appearance, tire series, and intended road use.
205/70R14 is a metric radial size where 205 identifies nominal section width in millimeters, 70 is the aspect ratio, R designates radial construction, and 14 is the wheel diameter in inches. On the 1981 BMW 733i, this is the conventional radial fitment and uses a standard 14-inch rim, making it the more familiar format for many modern buyers. Available choices include Maxxis, BFGoodrich, and Michelin, with sidewall treatments such as narrow whitewall, redline, dual-redline, raised white letter, and blackwall across several tire series. This size is the practical path when the car has inch-based 14-inch wheels and the goal is to compare period-style appearance against a more understated touring look.
220/55R390 is a metric radial size using a millimetric wheel designation, with 220 representing nominal section width in millimeters, 55 indicating aspect ratio, and 390 referring to the wheel diameter in millimeters rather than inches. For a 1981 BMW 733i, this size is tied to the Michelin TRX-style setup, so it should be treated as a distinct wheel-and-tire system rather than as another version of a 14-inch tire. The available product here is a Michelin TRX-B blackwall radial, which keeps the car in its TRX presentation. This size should be considered only after confirming the car still wears 390mm wheels, since a millimetric tire cannot be mounted on a conventional inch-diameter rim.
Sub-model fitment is straightforward here because the covered 1981 BMW 733i Base uses the same two radial tire sizes. The important step is not trim identification so much as confirming whether the car has conventional 14-inch wheels or the millimetric TRX wheel setup.
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1981 BMW 733i Base
The 1981 BMW 733i Base can use either the conventional 205/70R14 radial size or the millimetric 220/55R390 radial size. Tire selection therefore depends on the actual wheels installed on the car, followed by whether the goal is a traditional touring appearance, a sportier sidewall treatment, or retention of the TRX format.
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 1981 BMW 733i Tires for Sale
Available 1981 BMW 733i tire choices span 205/70R14 and 220/55R390 radials from Maxxis, BFGoodrich, and Michelin. Buyers can compare tire series and sidewall styles ranging from narrow whitewall and blackwall to redline, dual-redline, and raised white letter, while also checking the wheel format each size requires.
These FAQs focus on the two tire sizes used on the 1981 BMW 733i, how wheel format affects fitment, and how to choose among available radial, sidewall, and restoration-oriented tire options.
Tire Size & Fitment
What tire size fits a 1981 BMW 733i?
The 1981 BMW 733i uses two primary radial tire sizes: 205/70R14 and 220/55R390. Both apply to the 1981 BMW 733i Base, but they are not interchangeable because they belong to different wheel formats.
The key step is confirming which wheels are actually on the car. A 205/70R14 tire mounts on a conventional 14-inch wheel, while a 220/55R390 tire is built for a 390mm Michelin TRX-type wheel. Many cars from this era have had wheel changes over time, so checking the wheel diameter before ordering tires is more important than relying on appearance alone.
What size rim does a 1981 BMW 733i use?
A 1981 BMW 733i can be found with either a conventional 14-inch wheel for 205/70R14 tires or a 390mm wheel for 220/55R390 tires. The wheel size depends on which tire system is on the car.
That difference matters because 14-inch and 390mm wheels are close in concept but not the same in actual diameter. A millimetric TRX tire cannot be mounted on an inch-based wheel, and an inch-based tire cannot be mounted on a TRX wheel. Looking at the tire sidewall and measuring or confirming the wheel marking before choosing a tire avoids a costly fitment mistake.
Why does the 1981 BMW 733i have more than one tire size?
The 1981 BMW 733i has more than one tire size because it was fitted with two different radial tire systems: a conventional 205/70R14 setup and a 220/55R390 millimetric TRX setup. Both sizes belong to the same model year but correspond to different wheel formats.
For the owner, that means the right tire choice begins with the wheels rather than the body style. Some cars remain on their original type of wheel, while others may have been changed during decades of service. Once the wheel format is confirmed, the decision becomes much easier because each tire size has its own compatible products, sidewall styles, and visual character.
Choosing the Right Tire
What should I consider when choosing a 205/70R14 tire for a 1981 BMW 733i?
A 205/70R14 tire for a 1981 BMW 733i should first match the car’s actual 14-inch wheel setup. After that, the main considerations are radial construction details, sidewall style, tire series, and the rim-width range that best matches the wheel on the car.
This size offers several visual directions, from a more understated blackwall or narrow whitewall look to redline, dual-redline, or raised white letter styling. It also spans multiple brands and tire series, so the choice often comes down to whether the car is being kept close to a traditional luxury-sedan presentation or given a more individualized period-style appearance.
What sidewall styles are available for 1981 BMW 733i tires?
1981 BMW 733i tires are available with several sidewall styles, depending on size and tire series. In 205/70R14, choices include narrow whitewall, redline, dual-redline, raised white letter, and blackwall, while the 220/55R390 Michelin TRX-B is offered as a blackwall radial.
Sidewall style changes the car’s presentation more than many buyers expect. A blackwall keeps the look restrained and European, while whitewall or stripe treatments create a stronger vintage visual statement. The right choice depends on the car’s finish, wheels, and restoration direction, but the sidewall should always be chosen after the correct tire size and wheel type are confirmed.
What brands offer tires for the 1981 BMW 733i?
Tires for the 1981 BMW 733i are available from Maxxis, BFGoodrich, and Michelin. Brand availability depends on tire size, with 205/70R14 offering the broadest selection and 220/55R390 centered on the Michelin TRX-B.
Brand choice is only one part of the decision. The more useful comparison is how each product aligns with the car’s wheel format, desired sidewall treatment, tire series, and overall appearance. A 14-inch wheel opens up several visual and series options, while a TRX-equipped car points the decision toward preserving the millimetric setup with the correct wheel-specific tire.
Restoration & Appearance
Which tire should I choose for a period-style 1981 BMW 733i?
A period-style 1981 BMW 733i tire choice starts with the car’s actual wheel system. A car on conventional 14-inch wheels can use 205/70R14 in several traditional-looking radial series, while a car retaining its millimetric setup points toward the 220/55R390 Michelin TRX-B.
Appearance then becomes the deciding factor. Blackwall keeps a formal European touring look, while narrow whitewall, redline, or dual-redline creates a more personalized vintage presentation. Exact originality should be checked against marque-specific references or surviving vehicle history, but matching the wheel format first keeps the restoration conversation grounded in proper fitment.
How does tire construction affect the appearance of a restored 1981 BMW 733i?
On the 1981 BMW 733i, tire construction is simpler than on many older collector cars because both primary fitments are radial. The bigger appearance difference comes from whether the car wears conventional 14-inch radials or the distinctive millimetric TRX radial setup, along with the chosen sidewall treatment.
That means a restoration-minded owner is usually balancing wheel authenticity, sidewall style, and overall visual tone rather than choosing between bias-ply and radial construction. A blackwall TRX presentation gives the car one kind of early-1980s executive character, while 205/70R14 options can move the look toward either understated touring style or a more noticeable period-inspired accent.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1981 BMW 733i?
Yes, modifications can affect tire fitment on a 1981 BMW 733i. Wheel changes are especially important because this car may use either conventional 14-inch wheels with 205/70R14 tires or 390mm TRX wheels with 220/55R390 tires, and those systems are not cross-compatible.
Suspension changes, lowered ride height, aftermarket wheel widths, or offset changes can also alter clearance at the fenders and steering components. Even when the sidewall size looks close, the actual wheel format has to match first. Any modified car should be checked for wheel diameter, wheel width, and turning clearance before selecting a replacement tire.
What should I inspect before driving a 1981 BMW 733i on new tires?
Before driving a 1981 BMW 733i on new tires, inspect the wheels for the correct diameter and condition, confirm proper mounting for the chosen tire size, and check inflation pressure carefully. It is also wise to look over valve stems, wheel balance, and general suspension condition.
A collector-era sedan that has seen long storage should also be checked for brake drag, loose steering parts, and any signs of rubbing once the car is on the ground. A short test drive followed by another look at clearance and air retention helps catch small problems early, especially on a car that may have changed wheels or sat unused for extended periods.
How should tires on a collector 1981 BMW 733i be maintained?
Tires on a collector 1981 BMW 733i should be maintained with regular pressure checks, visual inspections, and attention to age-related condition. Even radial tires that show good tread can develop cracking, flat spotting, or air loss after long periods of light use or storage.
Storage habits matter as much as mileage on a car like this. Keeping the BMW away from prolonged sunlight, excess heat, moisture, and ozone sources helps preserve the rubber, and occasional movement can reduce long-term flat spotting. Any sign of cuts, bulges, unusual wear, or repeated pressure loss should be addressed before putting the car back into regular road use.
