305/45R17 Tire Size

All You Need to Know About 305/45R17 Tires

305/45R17 tires are 305 mm wide, with a 45% aspect ratio and a 17-inch wheel diameter, resulting in an overall diameter of ≈27.8 inches and a sidewall height of ≈5.4 inches. Approved rim width ranges for this size vary by manufacturer and should be confirmed against the specific tire's data sheet; published examples typically fall in the 9.5–11.5 inch range, but the measuring rim width should be verified before assuming compatibility.

At ≈12.0 inches wide, 305/45R17 occupies a much wider section class than most 17-inch performance sizes. Its ≈5.4-inch sidewall allows meaningful deformation under load, but the dominant effect comes from footprint width: more tread on the ground, more demand on wheel width and offset, and less margin at the inner suspension and outer fender.

305/45R17 Size Quick Specs

• Approved rim width range: 9.5–11.5"
• Width: 305 mm
• Sidewall height: 137.25 mm
• Overall diameter: ≈27.8"
• Wheel diameter: 17"

Note: The calculated overall diameter is ≈27.8 inches. Published product specs in this size also list variations up to 28.1 inches, as a small variation by manufacturer can still occur because tread depth and casing shape affect the final mounted dimensions.

305/45R17 Common Vehicle Fitment

305/45R17 is primarily a specialty performance size rather than a broad OEM replacement size. Current market examples are concentrated in performance and drag-oriented products, consistent with how this size is typically used: wide rear fitments on high-power rear-wheel-drive platforms and custom builds on 17-inch wheels.

Platforms where 305/45R17 appears in performance and aftermarket fitments include:

• Ford Mustang (SN95 and S197 generations) in wide rear configurations
• Chevrolet Camaro (fourth generation) drag and track builds
• Dodge Viper (first and second generation), which used wide 17-inch rear fitments
• Modified/Lowered Trucks & SUVs (such as Ford F-150, Chevy Silverado) 

These are aftermarket and build-specific applications. None should be assumed to fit without confirming wheel width, offset, inner clearance, and outer fender room for the specific vehicle configuration. A tire close in diameter to the original size can still fail fitment if the 12.0-inch section width contacts suspension components or bodywork.

305/45R17 Dimensions in Inches

The 305/45R17 is approximately 12.0 inches wide, 27.8 inches tall, and is 5.4 inches in sidewall height.

These measurements put 305/45R17 tires in a width-driven category. Compared with narrower 17-inch performance sizes, the main effect is not a dramatic change in height but a substantial increase in footprint width. The practical result is stronger straight-line traction potential and higher clearance sensitivity across wheel width, offset, and fender space.

305/45R17 in Inches: Full Measurement Set

• Overall diameter: ≈27.8"
• Width: ≈12.0"
• Sidewall height: ≈5.4"
• Wheel diameter: 17"
• Circumference: ≈87.34"

Comparison of 305/45R17 With Similar Tire Sizes

305/45R17 is most useful to compare against 275/50R17, which stays extremely close in diameter while reducing width, and 305/50R17, which keeps the same width but moves into a taller diameter class. These two comparisons separate the width change from the diameter change clearly.

305/45R17 vs 275/50R17

• Width: 305/45R17 is 30 mm wider
• Overall diameter: 275/50R17 is ≈0.03 inches (≈0.1%) larger than 305/45R17

From a diameter standpoint, the 275/50R17 and 305/45R17 sizes are effectively the same and can be interchanged. The real difference is width: 305/45R17 adds roughly 1.2 inches of nominal section width, which materially changes clearance demand, approved wheel width, and contact patch shape. This is a fitment-width comparison, not a gearing or speedometer comparison.

305/45R17 vs 305/50R17

• Width: identical at 305 mm
• Overall diameter: 305/50R17 is ≈1.20 inches (≈4.3%) larger than 305/45R17

At ≈4.3%, the difference exceeds the ±3% threshold, which places 305/50R17 and 305/45R17 sizes outside the direct substitution range. The taller 305/50R17 raises ride height, lowers rotational frequency, and creates measurable speedometer under-reading and gearing change. Because width stays constant, this comparison isolates the effect of diameter alone.

Before changing tire size from or to 305/45R17, review how the 3% rule applies and remember that diameter approval does not remove the need to verify wheel width, offset, and body clearance on a 305-section tire.