Pro-Trac Street Pro | N50-15

The Pro-Trac Street Pro N50-15 is designed for Pro Street builds, street machines, and hot rods that use an exceptionally wide tire profile. Its 12.65-inch section width and 27.87-inch overall diameter make it suited to builds seeking the wide rear-tire appearance associated with 1970s street machines. The product page specifically highlights mini-tubbed cars and combinations featuring wide rear tires with narrower front runners. Before purchasing, verify rear wheel compatibility and available space around the bodywork, suspension, and inner wheelhouse. The specified rim width is 8 to 10 inches, and actual fitment depends on the vehicle's axle configuration, wheel offset, and modifications.

The Pro-Trac Street Pro N50-15 has a 12.65-inch section width, making it a substantial tire that may require more clearance than a typical factory rear tire. Coker Tire identifies mini-tubbed vehicles as a suitable application, so a car with unmodified rear bodywork should not be assumed to accommodate the N50-15 without fitment checks. The listed overall diameter is 27.87 inches, which also affects vertical clearance within the wheel opening. Before selecting the N50-15, check the available space between the tire and inner wheelhouse, outer fender, suspension components, and bodywork throughout suspension travel. Wheel offset and rim width can change the installed tire's position and dimensions. Confirming these measurements is particularly important for stock-bodied muscle cars.

The Pro-Trac Street Pro N50-15 has an overall diameter of 27.87 inches and a static radius of 12.95 inches. If its diameter differs from your current rear tires, it will change the effective final-drive relationship at the wheels. A taller tire generally reduces engine RPM at a given road speed while making the effective gearing taller; a shorter tire generally has the opposite effect. The actual change depends on the diameter of your existing tires. The N50-15 also uses bias-ply construction, which can feel different from modern radial tires during cornering and while following road irregularities. Its wide 12.65-inch section width may affect steering effort and handling characteristics, depending on the vehicle setup. Compare the current tire diameter and confirm appropriate wheel fitment before purchasing.

The Pro-Trac Street Pro N50-15 is specifically positioned for street machines, Pro Street cars, and hot rods that need a wide, race-inspired appearance without using an actual racing slick on public roads. Its 12.65-inch section width, 27.87-inch overall diameter, and classic blackwall styling suit builds seeking the oversized rear-tire look associated with 1970s street machines. The product page identifies the tire as DOT-approved and describes its tread as tested for dry and wet conditions. However, the N50-15 is a bias-ply street tire, not a modern radial. Bias-ply construction can produce different tracking and handling behavior, particularly on uneven pavement. Verify the vehicle's fitment, wheel width of 8 to 10 inches, load requirements, and speed-rating suitability before regular street or highway use.

The Pro-Trac Street Pro N50-15 is specifically designed for wide rear applications such as Pro Street builds and mini-tubbed muscle cars. With a section width of 12.65 inches and an overall diameter of 27.87 inches, it fills out rear wheel wells aggressively and delivers the classic big-and-little stance. It is not intended for stock narrow wheel wells without modification.

Fitment depends heavily on available clearance, especially under suspension compression. Cars with factory wheel tubs will typically require modifications to avoid rubbing. This tire works best when paired with widened rear axles or mini-tub kits that accommodate its width and footprint.

The Pro-Trac Street Pro N50-15 is designed to fit wheels between 8.00 and 10.00 inches wide. Staying within this range ensures proper sidewall shape, optimal contact patch, and safe bead seating. Narrower wheels can distort the tire profile, while wider wheels may reduce sidewall support.

Using a 10-inch wheel will give the tire a slightly flatter footprint and more planted stance, while an 8-inch wheel will produce a more rounded sidewall look. Wheel width selection also affects clearance, so measuring backspacing and offset is just as important as width when dialing in fitment.

The closest radial equivalent to the Pro-Trac Street Pro N50-15 is 295/50R15. This conversion provides a similar overall diameter and width, making it a common alternative for those seeking radial ride characteristics.

However, the radial version will have a different sidewall profile and driving feel. The bias ply N50-15 delivers a more period-correct stance and softer sidewall flex, while the radial equivalent offers improved stability and reduced wandering at highway speeds.

With a section width of 12.65 inches, the Pro-Trac Street Pro N50-15 is comparable to wide metric sizes like 295 mm or slightly larger depending on the manufacturer. However, bias ply measurements can vary slightly based on mounting and inflation.

Unlike metric radials, bias ply tires tend to have more rounded shoulders, which affects how the width translates to actual contact patch. This means the visual width may appear larger than the effective tread contact area.

Mixing the Pro-Trac Street Pro N50-15 with radial front tires is possible but not ideal for consistent handling. Bias ply and radial constructions respond differently to road inputs, which can create unpredictable behavior at higher speeds.

If used together, expect some variation in tracking and steering response. Many traditional builds accept this trade-off for styling purposes, but for consistent driving feel, matching construction types front and rear is recommended.

The Pro-Trac Street Pro N50-15 is designed to deliver a race-inspired look with street usability. Unlike true slicks, it features a tread pattern tested for both dry and wet conditions, making it safer for everyday driving.

While it provides strong straight-line traction, it does not match the grip of dedicated racing slicks. However, it offers a much more practical solution for street machines that need to balance appearance with real-world drivability.

Yes, the wide contact patch of the Pro-Trac Street Pro N50-15 improves traction during straight-line acceleration. Its design is well-suited for street launches and mild drag-style driving.

The bias ply construction allows the tire to flex slightly, aiding grip under load. However, it is not a dedicated drag tire, so traction gains depend on surface conditions and vehicle setup.

The Pro-Trac Street Pro N50-15 uses bias ply construction, where internal cords are layered at angles to create a strong, flexible structure. This design was standard in vehicles through the 1970s.

Bias ply construction offers durability and a classic driving feel but tends to follow road imperfections more than radial tires. It is ideal for authenticity but requires adjustment in driving expectations.

The Pro-Trac Street Pro N50-15 is built for street use with a tested tread pattern and DOT approval. Its construction is durable enough for regular driving when properly maintained.

However, like most bias ply tires, it requires more attention to inflation and alignment. Proper care ensures longer life and consistent performance.

The 11/32 tread depth of the Pro-Trac Street Pro N50-15 provides a balance between traction and longevity. It offers enough depth for effective grip while maintaining a performance-oriented profile.

This depth also contributes to wet traction capabilities. However, as the tread wears, performance in wet conditions may decrease, requiring monitoring over time.

Inflation pressure has a significant impact on the Pro-Trac Street Pro N50-15’s performance. Lower pressure increases the contact patch but can lead to excessive heat and wear.

Higher pressure improves stability but reduces traction. Finding the correct balance is essential and may require slight adjustments based on driving conditions and vehicle setup.

Yes, the Pro-Trac Street Pro N50-15 is designed as a tubeless tire, allowing it to be mounted directly onto compatible wheels without the need for inner tubes.

Proper sealing between the tire bead and wheel is essential for maintaining air pressure. Ensure wheels are in good condition and free of damage before installation.

Before installing the Pro-Trac Street Pro N50-15, verify wheel width, backspacing, and clearance. Ensure the wheel falls within the 8 to 10 inch width range and that there is sufficient space for the tire’s width and diameter.

Also inspect suspension components and alignment. Proper preparation prevents fitment issues and ensures optimal performance after installation.