305/70R17 Tire Size

All You Need to Know About 305/70R17 Tires

305/70R17 tires are 305 mm wide, built on a 70% aspect ratio and a 17-inch wheel diameter, producing an overall diameter of ≈33.8 inches and a sidewall height of ≈8.4 inches. Rim width requirements vary by manufacturer, but most applications fall within roughly 8.0–10.0 inches, with 8.5 to 9.5 inches often being the optimal width for performance and proper sidewall shape.

The 305/70R17 size sits firmly in the 33-inch class, where both diameter and section width influence fitment at the same time. It is not a subtle change from most factory configurations - it alters clearance, gearing, and footprint simultaneously.

The ≈8.4-inch sidewall allows substantial vertical deformation, which improves traction on uneven terrain and helps maintain ground contact under load. At the same time, the ≈12-inch section width increases the tire’s lateral footprint, which enhances stability but reduces available clearance at both the suspension side and the fender line.

305/70R17 Size Quick Specs

• Approved rim width range: commonly 8.0"–10.0"
• Optimal rim width:  8.5"–9.5"
• Section width: 305 mm
• Sidewall height: ≈213.5 mm 
• Overall diameter: ≈33.8"
• Wheel diameter: 17"

Note: While the calculated OD of 305/70R17 size is ≈33.8, the actual diameter can vary slightly (≈+/-0.2 inches) depending on tread depth and casing construction.

305/70R17 Common Vehicle Fitment

305/70R17 is commonly selected for trucks and SUVs that have been modified for additional clearance, typically through lift kits or leveling adjustments. This size is commonly seen on: 

• Ford F-150 and Super Duty (modified setups)
• Chevrolet Silverado / GMC Sierra
• Ram 2500 / 3500
• Toyota Tundra, Tacoma, and 4Runner builds (often used for overlanding/oversize)
• Jeep Wrangler and Gladiator (lifted configurations)

With a diameter approaching 34 inches and a section width of ≈12 inches, the 305/70R17 size requires careful verification of inner clearance, outer fender space, steering articulation, and suspension compression - especially under load, where the tire expands beyond its static dimensions.

305/70R17 Dimensions in Inches

The 305/70R17 measures approximately 12.0 inches wide, 33.8 inches tall, and has an ≈8.4-inch sidewall. This geometry shifts the vehicle upward while simultaneously increasing footprint width. The result is improved off-road traction and ground clearance, but also a reduction in rotational speed relative to smaller tires, which influences gearing and speedometer calibration.

305/70R17 in Inches: Full Measurement Set

• Overall diameter: ≈33.8"
• Width: ≈12.0"
• Sidewall height: ≈8.4"
• Wheel diameter: 17"
• Circumference: ≈106.2"

Comparison of 305/70R17 With Similar Tire Sizes

305/70R17 is typically evaluated against 295/70R17, which stays close in diameter with reduced width, and 305/75R17, which increases height while keeping the same section width.

305/70R17 vs 295/70R17

• Width: 305/70R17 is 10 mm wider
• Overall diameter: 305/70R17 is ≈0.56 inches (≈1.7%) larger than 295/70R17

At ≈1.7%, the diameter difference between 305/70R17 and 295/70R17 remains within the accepted ±3% range, making these sizes interchangeable. The practical impact comes from width: the wider 305/70R17 increases footprint and requires additional clearance at the inner suspension and outer fender, along with confirmation of appropriate rim width.

305/70R17 vs 305/75R17

• Width: identical at 305 mm  
• Overall diameter: 305/75R17 is ≈1.18 inches (≈3.5%) larger than 305/70R17  

At ≈3.5%, the diameter difference between 305/75R17 and 305/70R17 exceeds the accepted ±3% threshold, excluding the direct swap possibility. The taller 305/75R17 increases ride height, reduces wheel rotation frequency, and introduces measurable speedometer under-reading and gearing change. Clearance under compression and steering must also be verified before considering this change.