1951 Mercedes-Benz 170 Tires

The 1951 Mercedes-Benz 170 uses more than one primary tire size, depending on the exact sub-model. Covered fitments include 550-16 bias-ply, 640-15 bias-ply, and 175R15 radial. The 170 D, Da & Db and 170 V, Va & Vb use 550-16, while the 170 S & Sb uses either 640-15 or 175R15 on 15-inch wheels.

That means the first job is identifying the exact sub-model and confirming the wheel diameter currently on the car. A 15-inch tire and a 16-inch tire are not interchangeable simply because they belong to the same model family, and any surviving car with older restorations or wheel changes should be checked carefully before selecting a replacement.

The 1951 Mercedes-Benz 170 uses either a 16-inch or 15-inch rim, depending on the sub-model and tire fitment. The 550-16 size is built for a 16-inch rim, while both 640-15 and 175R15 are 15-inch tire sizes. Rim diameter is one of the most important fitment checkpoints on this vehicle.

Confirm the wheel size on the car itself before choosing a tire, especially if the car has been restored, stored for years, or fitted with replacement wheels at some point in its life. Wheel width also matters when comparing products or considering a radial equivalent, because rim compatibility affects how the tire seats and how it clears the body and suspension.

No, the 1951 Mercedes-Benz 170 sub-models do not all use the same tire size. The 170 D, Da & Db and 170 V, Va & Vb use 550-16 bias-ply tires, while the 170 S & Sb uses 15-inch fitments and may take either 640-15 bias-ply or 175R15 radial, depending on the setup being matched.

That variation is why sub-model identification matters before comparing brands, sidewall styles, or construction types. It is also wise to verify what is actually mounted on the car today, since a decades-old collector vehicle may no longer be wearing the same wheels or tires it had earlier in its restoration history.

Radial equivalents for 640-15 include 175R15 as an 80-series metric radial, P175/75R15 as a P-metric 75-series radial, and P185/70R15 as a P-metric 70-series radial. A recommended rim-width range of 5-6 inches is associated with that equivalent comparison. No bias-look radial equivalent is identified for 640-15 in this fitment group.

Those sizes give different radial-format ways to compare against the original 640-15 bias-ply tire, but they should not be treated as automatic replacements. Wheel width, actual wheel diameter, tire dimensions, and available clearance around the fenders and suspension should all be checked before moving from the original bias-ply sizing to a radial alternative.

That depends on the sub-model, the wheel setup, and the goal for the car. The 1951 Mercedes-Benz 170 family includes both traditional bias-ply fitments and a 175R15 radial fitment on certain 170 S & Sb applications. Bias-ply keeps the car in a more traditional sizing and appearance range, while radial-format fitment may appeal to owners matching a 15-inch radial application or considering an equivalent to 640-15.

The decision should start with the exact sub-model and actual wheel diameter rather than personal preference alone. Owners focused on period-style presentation often stay with the primary bias-ply size, while drivers evaluating radial alternatives should compare rim width, wheel compatibility, and clearance before changing construction or profile family.

Start by confirming that the car’s original bias-ply size has a usable radial equivalent in the same rim diameter. For the 640-15 fitment, 175R15, P175/75R15, and P185/70R15 are the relevant radial-equivalent sizes, and the comparison includes a recommended 5-6 inch rim-width range. The 550-16 fitment does not have a radial equivalent identified here.

Beyond the size comparison, inspect the actual wheel width, the condition of the wheels, and the clearance available at full steering lock and suspension travel. A collector car may also have replacement wheels, tired springs, or body repairs that affect space around the tire, so the full package should be evaluated before making the construction change.

The main considerations are the exact sub-model, the correct tire size, the wheel diameter, and whether the car should stay with a bias-ply fitment or use a radial-format option where applicable. On this model family, that means separating 550-16 applications from 15-inch 640-15 and 175R15 applications before looking at brands or appearance choices.

Once the basic fitment is confirmed, compare sidewall style, tire series, and rim-width compatibility where those details are available. A buyer restoring for traditional presentation may prioritize blackwall or whitewall appearance, while a car intended for regular road use may prompt closer attention to construction type and whether a radial equivalent is being considered.

Sidewall choices for the 1951 Mercedes-Benz 170 include blackwall, wide whitewall, and narrow whitewall, depending on the tire size and product selected. The 550-16 fitment is offered in blackwall and wide whitewall, while the 640-15 fitment expands the appearance range with blackwall, wide whitewall, and narrow whitewall options.

That variety lets the tire support different presentation goals without changing the underlying size. A blackwall often gives a restrained, utilitarian look, while whitewall treatments create a more formal restoration-oriented appearance. The important point is to choose the sidewall style only after the correct size and wheel diameter have been confirmed for the specific 170 sub-model.

Tires for the 1951 Mercedes-Benz 170 are available from Excelsior, Avon, BFGoodrich, and Firestone across the covered bias-ply fitments. Brand availability varies by size, with 550-16 and 640-15 each offering multiple brand choices. Several tire series also appear within those brands, including Firestone Classic Bias Ply, Silvertown Classic Bias Ply, Tourist Crossply, Super Safety Crossply, and Excelsior Bias Ply.

The practical choice is less about ranking brands and more about matching the correct size with the visual style and product character that suits the car. Once size and wheel diameter are settled, compare sidewall treatment, rim-width specification where given, and whether the tire supports the traditional look or driving setup you want for the vehicle.

For a period-style 1951 Mercedes-Benz 170, the starting point is the primary fitment for the exact sub-model rather than a universal size across the whole model family. That means 550-16 bias-ply for the 170 D, Da & Db and 170 V, Va & Vb, or 640-15 bias-ply for 15-inch bias-ply 170 S & Sb applications. Staying with the correct primary sizing preserves the car’s traditional stance and presentation more closely than jumping straight to a modern-format substitute.

After the size is settled, the appearance decision usually comes down to blackwall or one of the available whitewall treatments. Buyers pursuing exact historical authenticity should still compare their choice against marque references, photographs, or restoration records for the specific car, since a period-style tire is not automatically the same thing as an exact original-delivery specification.

Tire construction changes more than the hidden carcass of the tire on a restored 1951 Mercedes-Benz 170. A bias-ply tire such as 550-16 or 640-15 presents the car in a more traditional early-1950s style, while a radial-format size such as 175R15 introduces a more modern sizing convention even when it still suits a correct 15-inch wheel application.

That visual difference matters on a restrained, formal car like the 170, where sidewall shape and overall tire presentation contribute strongly to the finished look. Owners restoring for show, touring, or personal enjoyment should decide early whether traditional appearance or a radial-format approach matters more, then verify that the chosen construction also matches the proper sub-model and wheel setup.

Yes, modifications can affect tire fitment on a 1951 Mercedes-Benz 170 even when the tire size itself is correct for the model family. Aftermarket wheels, different wheel widths, suspension changes, body repairs, or lowered ride height can alter how a 550-16, 640-15, or 175R15 tire sits in the wheel opening and how much clearance remains during steering and suspension movement.

A modified car should be checked as it exists today rather than assumed to match original fitment conditions. Measure the wheel diameter, confirm the wheel width, and look closely at fender, steering, and suspension clearance before choosing a replacement tire, especially when moving between bias-ply and radial constructions on a 15-inch setup.

Before driving a 1951 Mercedes-Benz 170 on new tires, inspect the wheels for condition and correct diameter, make sure each tire is seated properly, and confirm there is no interference at the fenders, suspension, or steering components. It is also wise to verify inflation, look for any signs of uneven stance, and make sure older tubes or valve hardware are not being reused carelessly on a long-stored car.

The first road test should be cautious and short enough to catch rubbing, vibration, or air-loss issues early. On a collector vehicle that may have sat for long periods, a broader pre-drive check is smart as well, including brakes, steering play, suspension wear, and wheel fastener condition so the new tires are not asked to compensate for other aging mechanical problems.

Tires on a collector 1951 Mercedes-Benz 170 should be maintained with regular pressure checks, visual inspections, and careful storage habits. Even if the car is driven only occasionally, the tires should be checked for cracking, bulges, cuts, uneven wear, and slow air loss. Bias-ply and radial tires alike benefit from being kept clean and protected from long periods of direct sun, excess heat, and ozone exposure.

A low-mileage collector car can still have tire issues simply from age and inactivity, so condition matters as much as tread depth. Rolling the car periodically, avoiding prolonged flat spotting, and inspecting the tires before each outing helps preserve both ride quality and safety. Any tire showing age-related deterioration should be evaluated before road use, even if it still looks lightly worn.