The 1959 De Soto MS 1-L-8 Firesweep came at the end of De Soto’s fin-era styling period, when full-size American wagons and passenger cars carried a strong visual presence and a distinctly late-1950s road feel. That character matters when choosing tires, because this Firesweep uses 14-inch bias-ply fitments in either 800-14 or 850-14 depending on the vehicle’s setup. Both sizes keep the car in its proper vintage sizing language, while available choices include blackwall, narrow whitewall, and wide whitewall presentations, along with modern radial equivalents for buyers considering a different construction. The right choice starts with confirming size, then balancing appearance, wheel compatibility, and intended driving use.
Which Tire Size Is Right for The 1959 De Soto MS 1-L-8 Firesweep
The 1959 De Soto MS 1-L-8 Firesweep uses two primary tire sizes, and both are bias-ply sizes built for 14-inch rims. Because the covered sub-models can use either 800-14 or 850-14, the first step is confirming which size is on the car now and whether the wheel setup matches it. Once that is settled, the decision shifts to sidewall style, brand and series differences, or whether a radial equivalent is worth evaluating.
An 800-14 numeric bias-ply size uses the leading number as a nominal section-width designation, so the tire falls into the traditional 8.00-inch width class and mounts on a 14-inch wheel. On a 1959 De Soto MS 1-L-8 Firesweep, this keeps the car in a correct vintage sizing format and preserves the look and character associated with a late-1950s bias-ply setup. Available choices include BFGoodrich, Universal Vintage Tire, and Goodyear, with blackwall, narrow whitewall, and wide whitewall styles across series such as Silvertown Classic Bias Ply, Universal Classic Bias Ply, and Custom Super Cushion. This size is worth choosing when the car’s wheel and current fitment point to 800-14 and you want to compare appearance and brand options within that original-style construction.
An 850-14 follows the same vintage numeric bias-ply sizing system, with the 8.50 designation indicating a wider nominal section class than 800-14, while still using a 14-inch rim. For the 1959 De Soto MS 1-L-8 Firesweep, it remains a period-style bias-ply fitment rather than a modern metric size, which makes construction and wheel match more important than simply comparing numbers to newer tires. In this size, BFGoodrich offers narrow whitewall and wide whitewall versions in the Silvertown Classic Bias Ply series. This size deserves a closer look when the car already carries 850-14 tires or when wheel width and vehicle setup support that larger primary fitment.
Fitment across the covered 1959 De Soto MS 1-L-8 Firesweep sub-models is straightforward in one sense: each one uses the same two primary bias-ply sizes on 14-inch rims. Checking the exact sub-model still matters, because tire selection should follow the car’s actual wheel setup and the size already established on the vehicle.
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1959 De Soto MS 1-L-8 Firesweep 2 Seat Wagon
The 1959 De Soto MS 1-L-8 Firesweep 2 Seat Wagon uses the same pair of primary 14-inch bias-ply tire sizes found across the covered Firesweep range. That means the main decision is not trim-specific fitment, but confirming whether the wagon is set up for 800-14 or 850-14 before comparing whitewall treatments, brand choices, or radial alternatives.
The 1959 De Soto MS 1-L-8 Firesweep 3 Seat Wagon shares the same 14-inch bias-ply tire-size choices as the other covered sub-models. Tire selection comes down to identifying which of the two primary sizes the car actually uses, then choosing the sidewall style and construction approach that best suits restoration goals and road use.
The 1959 De Soto MS 1-L-8 Firesweep Base follows the same primary fitment pattern, with 800-14 and 850-14 bias-ply sizes used on 14-inch rims. That keeps the focus on confirming the car’s existing wheel and tire setup, then selecting among period-style bias-ply options or reviewing radial equivalents where they are available.
Bias-Ply to Radial Tire Conversion for the 1959 De Soto MS 1-L-8 Firesweep
The original 800-14 tire size has four radial-equivalent choices, while 850-14 has three. For 800-14, the available alternatives are 205R14 as an 80-series metric radial, P215/75R14 as a 75-series P-metric radial, P225/70R14 as a 70-series P-metric radial, and 800R14 as a bias-look radial. For 850-14, the equivalents are 215R14, P225/75R14, and P235/70R14. These options span traditional metric, P-metric, and bias-look presentations, with a 5-7 inch recommended rim-width range; wheel fit, dimensions, and clearance should still be checked before changing construction or size format.
Modern Radial Equivalents
205R14
Equivalent 80-series Metric Radial (800-14)
P215/75R14
Equivalent P-metric 75-series Radial (800-14)
P225/70R14
Equivalent P-metric 70-series Radial (800-14)
800R14
Bias-look Radial Equivalent (800-14)
215R14
Equivalent 80-series Metric Radial (850-14)
P225/75R14
Equivalent P-metric 75-series Radial (850-14)
P235/70R14
Equivalent P-metric 70-series Radial (850-14)
Important Considerations When Replacing Bias Ply With Radial
Compare overall diameter and section width carefully to ensure proper fit.
Verify recommended rim range (5-7 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 1959 De Soto MS 1-L-8 Firesweep Tires for Sale
Available 1959 De Soto MS 1-L-8 Firesweep tires center on 800-14 and 850-14 bias-ply fitments from BFGoodrich, Goodyear, and Universal Vintage Tire. The product grid lets you compare series such as Silvertown Classic Bias Ply, Universal Classic Bias Ply, and Custom Super Cushion, along with blackwall, narrow whitewall, and wide whitewall appearances.
Owners of a 1959 De Soto MS 1-L-8 Firesweep usually need clarity on the two primary tire sizes, 14-inch rim fitment, bias-ply versus radial choices, and how whitewall or blackwall options affect the car’s overall presentation.
Tire Size & Fitment
What tire size fits a 1959 De Soto MS 1-L-8 Firesweep?
The 1959 De Soto MS 1-L-8 Firesweep uses two primary tire sizes: 800-14 and 850-14. Both are vintage numeric bias-ply sizes designed for 14-inch rims, and both appear across the covered Firesweep sub-models, including the Base, 2 Seat Wagon, and 3 Seat Wagon.
That means the key step is confirming which size your car actually carries before choosing a replacement. Check the existing tire size, wheel width, and overall setup, especially if the car has been restored or modified at some point. Once the correct primary size is confirmed, the choice becomes one of sidewall appearance, brand and series, or whether to consider a radial equivalent.
What size rim does a 1959 De Soto MS 1-L-8 Firesweep use?
The 1959 De Soto MS 1-L-8 Firesweep uses a 14-inch rim with both of its primary tire sizes. That applies to 800-14 and 850-14, so wheel diameter remains consistent even though the car can use more than one bias-ply size.
Rim diameter is only one part of the fitment picture, so it should not be treated as full interchangeability by itself. Wheel width still matters, especially when comparing 800-14 and 850-14 or looking at radial equivalents. A close look at the wheel stamping, current tire size, and available clearance around suspension and fenders will help narrow the proper choice.
Do all 1959 De Soto MS 1-L-8 Firesweep sub-models use the same tire size?
The covered 1959 De Soto MS 1-L-8 Firesweep sub-models all share the same pair of primary tire sizes: 800-14 and 850-14. That includes the Base, 2 Seat Wagon, and 3 Seat Wagon, and both sizes are bias-ply fitments for 14-inch rims.
Shared fitment across sub-models makes the search easier, but it does not remove the need to verify the car in front of you. A Firesweep that has had wheel changes, suspension work, or prior replacement tires may be set up around one of those sizes more appropriately than the other. Matching the replacement tire to the actual wheel and vehicle setup remains the safest approach.
Bias-Ply & Radial Options
Is 800-14 a bias-ply or radial tire for the 1959 De Soto MS 1-L-8 Firesweep?
For the 1959 De Soto MS 1-L-8 Firesweep, 800-14 is a primary bias-ply tire size. It uses the traditional vintage numeric sizing system and belongs to the original-style fitment language of a late-1950s American car rather than a modern metric radial format.
That matters because a buyer may be deciding between keeping a period-style bias-ply presentation or moving to a radial equivalent for a different driving character. The wheel itself should still be checked carefully before any construction change, including rim width and tire clearance. Keeping the same size code does not make a radial conversion automatic.
What radial tire sizes are equivalent to 800-14 and 850-14?
For 800-14, radial equivalents include 205R14 as an 80-series metric radial, P215/75R14 as a 75-series P-metric radial, P225/70R14 as a 70-series P-metric radial, and 800R14 as a bias-look radial. For 850-14, the radial equivalents are 215R14, P225/75R14, and P235/70R14.
Those choices give the Firesweep owner several ways to stay close to the original tire’s general role while using a radial format. Even so, each alternative should be treated as a size to evaluate, not an automatic swap. A 5-7 inch recommended rim-width range is associated with both primary sizes, and wheel compatibility plus vehicle clearance still deserve a careful check.
What should I check before converting my 1959 De Soto MS 1-L-8 Firesweep from bias-ply to radial tires?
Start by confirming the car’s actual primary size, either 800-14 or 850-14, and then compare the correct radial equivalent options for that size. On the 1959 De Soto MS 1-L-8 Firesweep, both primary fitments use 14-inch wheels, and the radial-equivalent rim-width guidance falls in the 5-7 inch range.
The next step is checking the real-world setup on the car, including wheel width, overall tire clearance at the fenders and suspension, and the condition of steering and suspension components. A radial equivalent changes more than the lettering on the sidewall, so the decision should also reflect whether the car is being kept in a restoration-oriented bias-ply presentation or prepared for broader road use.
Choosing the Right Tire
What should I consider when choosing a 800-14 or 850-14 tire for a 1959 De Soto MS 1-L-8 Firesweep?
The first consideration is confirming whether your 1959 De Soto MS 1-L-8 Firesweep is set up for 800-14 or 850-14, since both are primary bias-ply sizes for 14-inch wheels. After size is confirmed, compare construction, sidewall style, brand, tire series, and wheel-width suitability rather than focusing on appearance alone.
An owner restoring a late-1950s De Soto may lean toward a period-style whitewall presentation, while a buyer using the car more regularly may spend more time comparing equivalent radial options. Product details such as max load capacity and rim-width guidance can also help narrow the field. The right tire is the one that matches the car’s actual setup and intended use.
What sidewall styles are available for 1959 De Soto MS 1-L-8 Firesweep tires?
Sidewall choices for the 1959 De Soto MS 1-L-8 Firesweep include blackwall, narrow whitewall, and wide whitewall, depending on tire size and product line. The 800-14 selection shows the broadest spread, while 850-14 is available in narrow whitewall and wide whitewall versions.
That variety lets the tire play a major role in the car’s finished look without changing the primary vintage fitment. A blackwall gives a more restrained appearance, while whitewall versions move the presentation toward a stronger late-1950s visual statement. Choosing among them should follow the actual tire size first, then the appearance you want the Firesweep to carry.
What brands offer tires for the 1959 De Soto MS 1-L-8 Firesweep?
Tires for the 1959 De Soto MS 1-L-8 Firesweep are available from BFGoodrich, Goodyear, and Universal Vintage Tire. Brand availability depends on size, with 800-14 showing the broadest mix and 850-14 centered on BFGoodrich offerings in the Silvertown Classic Bias Ply line.
Brand choice is most useful when it helps narrow the combination of sidewall style, tire series, and fitment details you want. One buyer may be looking for a particular whitewall presentation, while another may want a blackwall option in 800-14. Compare each tire within the correct size first, then use brand and series differences to refine the final selection.
Restoration & Appearance
Which tire should I choose for a period-style 1959 De Soto MS 1-L-8 Firesweep?
A period-style 1959 De Soto MS 1-L-8 Firesweep starts with the correct primary bias-ply size for the car, either 800-14 or 850-14. From there, the choice usually comes down to the visual character you want, such as blackwall, narrow whitewall, or wide whitewall, while staying within a vintage-style construction.
That approach preserves the look and sizing language most closely associated with a full-size American car of this era. If exact originality matters beyond general period style, it is worth comparing the car against marque literature, restoration references, or club knowledge before settling on a whitewall width or brand treatment. Tire appearance can change the whole stance of the vehicle.
How does tire construction affect the appearance of a restored 1959 De Soto MS 1-L-8 Firesweep?
On a restored 1959 De Soto MS 1-L-8 Firesweep, bias-ply construction supports the traditional sidewall shape and overall presentation associated with the car’s original era. Radial equivalents can still be appropriate for some owners, but they change the visual language away from a purely vintage bias-ply look.
That difference becomes more noticeable when the car is viewed as a complete restoration rather than just a driver. Sidewall style adds another layer, since narrow and wide whitewalls create very different impressions even within the same basic size. Choosing construction should therefore reflect whether the Firesweep is being finished for historical appearance, regular road use, or a balance of both.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1959 De Soto MS 1-L-8 Firesweep?
Yes, modifications can affect tire fitment on a 1959 De Soto MS 1-L-8 Firesweep even when the tire size itself looks correct on paper. Changes to wheels, wheel width, ride height, springs, steering components, or body clearance can all influence whether an 800-14, 850-14, or radial equivalent remains a sensible choice.
A car with aftermarket wheels deserves extra attention because matching the 14-inch diameter alone is not enough. Clearance at full steering lock, suspension travel, and the space under the fender opening all matter. Any owner dealing with a modified Firesweep should confirm the actual wheel and chassis setup before selecting between the car’s primary bias-ply sizes or a radial alternative.
What should I inspect before driving a 1959 De Soto MS 1-L-8 Firesweep on new tires?
Before driving a 1959 De Soto MS 1-L-8 Firesweep on new tires, inspect the wheels for correct diameter and general condition, and make sure the selected tire size matches the car’s setup. It is also wise to look over suspension and steering parts, because worn components can affect how any new tire behaves on the road.
A final walkaround should include tire pressure, valve condition, visible clearance at the fenders and chassis, and a check for anything that could rub once the car is moving. After the first short drive, recheck pressure and inspect for any signs of contact. Collector cars often reveal fitment issues only after they are back in motion.
How should 800-14 or 850-14 tires on a collector 1959 De Soto MS 1-L-8 Firesweep be maintained?
Collector-car tires on a 1959 De Soto MS 1-L-8 Firesweep should be maintained with regular pressure checks, visual inspections, and careful storage habits. Whether the car wears 800-14 or 850-14 tires, watch for cracking, bulges, cuts, uneven wear, and slow air loss, especially if the vehicle spends long periods parked.
Storage conditions matter as much as mileage on a seldom-driven car. Keeping the Firesweep away from prolonged sunlight, moisture, excessive heat, and ozone-producing equipment can help protect the tires between drives. It also helps to inspect the tires before any longer outing rather than assuming low use means low risk. Age and inactivity can be as important as tread depth.
