The 1966 Humber Sceptre sits in the later Rootes era, blending compact British saloon proportions with the more upscale character that made the Sceptre distinct from ordinary family transport. For owners keeping one on the road today, tire choice is part of preserving that refined period feel without overlooking practical drivability. This model uses either a 600-13 bias-ply fitment or a 165R13 radial on a 13-inch rim, so construction choice matters as much as size. Available options range from traditional whitewall bias-ply styles to blackwall radial choices from Michelin and Dunlop. The right selection depends on whether appearance, restoration character, or everyday road manners takes priority.
Which Tire Size Is Right for The 1966 Humber Sceptre
The 1966 Humber Sceptre uses two primary tire sizes, and both fit a 13-inch rim. The key distinction is construction: 600-13 is a bias-ply fitment, while 165R13 is a radial fitment. Before choosing a tire, confirm whether the car is being kept in a more traditional period-style setup or has already been running on radial tires, since that will shape the most sensible direction.
165R13 is a Euro-metric radial size in which 165 identifies the nominal section width in millimeters, R indicates radial construction, and 13 is the wheel diameter in inches. On the 1966 Humber Sceptre, this size represents the radial fitment path and suits owners looking for a later-style radial presentation on the correct rim diameter. Available choices include Michelin XAS-FF, Michelin XAS, and Dunlop SP Sport Aquajet, all in blackwall form. This size is worth evaluating when road use, radial construction, and a more understated sidewall appearance matter more than a traditional bias-ply look.
600-13 is a numeric bias-ply size, where the 600 designation refers to the tire's nominal section width class and 13 identifies the rim diameter in inches. For the 1966 Humber Sceptre, this is the period-style bias-ply fitment and keeps the car in a more traditional construction type. BFGoodrich offerings in the Silvertown Classic Bias Ply series are available with either a 2.00-inch whitewall or a 1.00-inch whitewall. This size makes the most sense when maintaining vintage tire character is the goal and the wheel setup matches the narrower rim-width requirements typical of the bias-ply format.
Fitment for the covered 1966 Humber Sceptre sub-model is straightforward, because the Sceptre II uses the same two primary tire sizes on a 13-inch rim. The main decision is not sub-model identification so much as choosing between the bias-ply and radial fitment paths.
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1966 Humber Sceptre II
The 1966 Humber Sceptre II uses both 165R13 radial and 600-13 bias-ply tire fitments. That gives owners a choice between a blackwall radial presentation and a more traditional whitewall bias-ply look, while still keeping the correct 13-inch wheel diameter in view.
Bias-Ply to Radial Tire Conversion for the 1966 Humber Sceptre
For the original 600-13 size, three radial-equivalent options are available. 165R13 is the 80-series metric radial equivalent, P165/75R13 is the P-metric 75-series radial alternative, and P175/70R13 is the P-metric 70-series radial alternative. These choices differ mainly by sizing convention and profile family rather than serving as the same type of tire. A 4- to 5-inch recommended rim-width range is associated with this conversion path, so wheel width, overall dimensions, and vehicle clearance should all be checked before changing from the original bias-ply size.
Modern Radial Equivalents
165R13
Equivalent 80-series Metric Radial (600-13)
P165/75R13
Equivalent P-metric 75-series Radial (600-13)
P175/70R13
Equivalent P-metric 70-series Radial (600-13)
Important Considerations When Replacing Bias Ply With Radial
Compare overall diameter and section width carefully to ensure proper fit.
Verify recommended rim range (4-5 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 1966 Humber Sceptre Tires for Sale
Available 1966 Humber Sceptre tire choices span Michelin, Dunlop, and BFGoodrich, with radial blackwall options in 165R13 and bias-ply whitewall options in 600-13. The product grid is most useful for comparing construction, tire series, sidewall treatment, and rim-width compatibility.
Common 1966 Humber Sceptre tire questions usually center on 165R13 versus 600-13, 13-inch rim fitment, radial-equivalent choices, and how sidewall style and construction affect a restoration-minded or road-use setup.
Tire Size & Fitment
What tire size fits a 1966 Humber Sceptre?
The 1966 Humber Sceptre uses two tire sizes: 165R13 in radial construction and 600-13 in bias-ply construction. Both are 13-inch fitments, but they represent different sizing systems and different approaches to how the car is set up.
The practical choice is deciding whether the car should stay with a traditional bias-ply presentation or run on a radial fitment. Checking the wheel width, the current tire type already on the car, and the intended use of the vehicle will help narrow the decision before moving to product and sidewall selection.
What size rim does a 1966 Humber Sceptre use?
The 1966 Humber Sceptre uses a 13-inch rim diameter with both of its primary tire sizes. That applies to the 165R13 radial fitment and the 600-13 bias-ply fitment, so the wheel diameter remains consistent even though the tire construction changes.
Wheel diameter is only the first check, because tire selection also depends on wheel width and the style of tire being considered. A radial and a bias-ply can share the same rim diameter while still having different width requirements, so the actual wheel dimensions should be confirmed before changing construction types.
What does 600-13 mean on a 1966 Humber Sceptre?
600-13 is a numeric bias-ply size. The 600 portion refers to the tire's nominal section width class, while 13 identifies the wheel diameter in inches. On the 1966 Humber Sceptre, it is the bias-ply fitment rather than the radial one.
That matters because a 600-13 tire is not just a different label for 165R13; it also reflects a different construction type and a different period-style appearance. Owners choosing 600-13 should also pay attention to the narrower rim-width requirements common to this size and confirm that the current wheels match that setup.
Bias-Ply & Radial Options
Is 600-13 a bias-ply or radial tire for the 1966 Humber Sceptre?
600-13 is the bias-ply tire size for the 1966 Humber Sceptre. The radial fitment on this model is 165R13, so the two sizes are tied not only to different sizing systems but also to different construction types.
That distinction affects more than appearance. Bias-ply and radial tires can call for different wheel-width considerations and can give the car a different visual character. Anyone moving from one construction to the other should confirm the wheel setup, compare the overall fit on the car, and make sure the change suits the way the Sceptre will be driven.
What radial tire sizes are equivalent to 600-13?
Radial equivalents for 600-13 include 165R13 as an 80-series metric radial, P165/75R13 as a P-metric 75-series radial, and P175/70R13 as a P-metric 70-series radial. These are recognized alternatives to the original bias-ply size rather than additional primary factory-style fitments.
Each equivalent uses a different sizing convention, so the choice is not only about switching to radial construction. The wheel should be checked against the 4- to 5-inch recommended rim-width range tied to the 600-13 conversion path, and the finished setup should be reviewed for clearance and overall compatibility before changing sizes.
Should I use bias-ply or radial tires on a 1966 Humber Sceptre?
Both approaches are valid on a 1966 Humber Sceptre because the car has a 600-13 bias-ply fitment and a 165R13 radial fitment. The better choice depends on what matters most to the owner: traditional presentation, construction type, and sidewall style, or a radial-based setup already established on the car.
A restoration-minded owner may lean toward the 600-13 bias-ply route, especially with whitewall styling available, while a road-use-focused owner may prefer staying with the 165R13 radial path. The decision should also take the wheel width, existing suspension setup, and the car's current stance into account rather than relying on size designation alone.
Choosing the Right Tire
What should I consider when choosing a 1966 Humber Sceptre tire?
Start with the correct primary size and construction for the direction the car is taking: 600-13 for bias-ply or 165R13 for radial. After that, the main factors are 13-inch wheel compatibility, rim-width suitability, sidewall appearance, and whether the car is being preserved with a more traditional look or used in a radial setup.
The available product mix makes those decisions visible. Bias-ply options focus on whitewall presentation, while radial choices stay with blackwall styling from Michelin and Dunlop. Looking at tire series, construction, and wheel-width requirements side by side will usually tell an owner more than simply choosing whichever tire matches the rim diameter.
What sidewall styles are available for 1966 Humber Sceptre tires?
The 1966 Humber Sceptre has both blackwall and whitewall choices, depending on tire size and construction. The 165R13 radial products are blackwall tires, while the 600-13 bias-ply products are offered with either a narrow whitewall or a wider 2.00-inch whitewall treatment.
That sidewall choice can change the car's overall presentation more than many owners expect. A blackwall radial gives the Sceptre a cleaner later-style look, while the whitewall bias-ply options create a more traditional visual effect. The right choice usually comes down to whether the car is being styled for period flavor or for a simpler radial appearance.
What brands offer tires for the 1966 Humber Sceptre?
Michelin, Dunlop, and BFGoodrich all offer tire options for the 1966 Humber Sceptre. Michelin and Dunlop cover the 165R13 radial fitment, while BFGoodrich supplies the 600-13 bias-ply choices in the Silvertown Classic Bias Ply series.
Brand choice should still come after confirming the correct size and construction path. Once that is settled, the more useful comparison points are the series offered in that size, the available sidewall style, and the wheel-width range tied to the tire. That approach keeps the decision focused on fitment and presentation rather than on brand name alone.
Restoration & Appearance
Which tire should I choose for a period-style 1966 Humber Sceptre?
For a period-style 1966 Humber Sceptre, the 600-13 bias-ply fitment is the most traditional starting point. It keeps the vintage numeric sizing format and is available in whitewall treatments that suit the formal, upscale character often associated with a mid-1960s British saloon.
That does not automatically make every whitewall version historically exact for every car, since originality details can vary by market, delivery, and owner preference over time. Buyers chasing a more exact restoration should compare tire appearance against marque references, period photography, or other Humber-specific documentation before settling on sidewall width.
How does tire construction affect the appearance of a restored 1966 Humber Sceptre?
Tire construction affects both stance and visual character on a restored 1966 Humber Sceptre. A 600-13 bias-ply presents the car in a more traditional vintage format, while a 165R13 radial gives it a more modernized look even though both use the same 13-inch rim diameter.
Sidewall styling reinforces that difference. Whitewall bias-ply tires create a distinctly period-oriented presentation, while blackwall radials appear cleaner and more understated. Owners restoring for touring use may accept that tradeoff, but anyone emphasizing authenticity in appearance should decide on construction and sidewall style before moving on to brand or tire series.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1966 Humber Sceptre?
Yes, modifications can affect tire fitment on a 1966 Humber Sceptre even when the tire size itself is correct. Changes to wheel width, aftermarket wheel design, suspension height, or body clearance can alter how a 165R13 radial or 600-13 bias-ply sits and moves within the wheel opening.
That matters most when changing construction type or moving from a stock-style wheel to a different setup. The safest approach is to confirm the actual rim dimensions on the car, then check steering clearance and fender space at full travel. A collector car that has been altered should always be measured as it sits today.
What should I inspect before driving a 1966 Humber Sceptre on new tires?
Before driving a 1966 Humber Sceptre on new tires, inspect the wheels for correct diameter and condition, confirm proper inflation, and look over the valve stems, lug hardware, and general mounting quality. It is also worth checking that the tires clear the suspension and bodywork throughout steering movement.
A low-use collector car deserves a broader walk-around before any serious road time. Brake response, steering free play, wheel-bearing condition, and old suspension bushings can influence how well new tires perform. Taking a short local drive first helps confirm that the car tracks cleanly and that nothing rubs once the tires settle in.
How should 1966 Humber Sceptre tires be maintained?
Tires on a 1966 Humber Sceptre should be maintained with regular pressure checks, visual inspections, and attention to age-related deterioration. Whether the car runs 165R13 radials or 600-13 bias-ply tires, watch for cracking, cuts, bulges, irregular wear, or slow air loss, especially if the car is driven infrequently.
Storage conditions matter just as much as mileage on an older collector car. Keeping the Sceptre away from prolonged sunlight, heat, moisture, and ozone sources helps preserve the rubber over time. Even tires with good tread should be inspected closely before longer trips, since age and storage history often tell more than tread depth alone.
