235/40R17 Tire Size

All You Need to Know About 235/40R17 Tires

235/40R17 tires are 235 mm wide, with a 40% aspect ratio and a 17-inch wheel diameter, producing an overall diameter of 24.4 inches and a sidewall height of 3.70 inches.

The 235/40R17 size falls into the ultra-low-profile performance category, where minimal sidewall height is used to maximize steering precision, cornering stability, and road feedback.

Compared to taller sizes like 235/45R17, the 235/40R17 reduces both overall diameter and sidewall height, lowering ride height and limiting sidewall flex. This results in sharper handling response but reduced impact absorption, making it more suitable for performance-oriented setups than comfort-focused driving.

Where a P235/40R17 specification is used, it indicates the same dimensional size built to passenger-load standards. While dimensions remain identical, load capacity and operating conditions vary depending on construction type.

235/40R17 Size Quick Specs

• Approved rim width range: 8.0–9.5"
• Width: 235 mm
• Sidewall height: 94.0 mm
• Overall diameter: 24.4"
• Wheel diameter: 17 in

Note: The calculated overall diameter of 235/40R17 is ≈24.4 inches. Minor variations may occur depending on the manufacturer's design and tread pattern rather than the nominal size itself. Mounting 235/40R17 tires within the approved rim width range also affects measured section width and sidewall stance, without changing the nominal diameter.

235/40R17 Common Vehicle Fitment

235/40R17 is typically used on sport compacts and performance-oriented sedans configured with wider wheels and lower-profile tires. Common U.S.-market applications include:

• Volkswagen Golf GTI (modified or performance setups)
• Honda Civic (performance builds and aftermarket fitments)
• BMW 3 Series (performance-oriented configurations)
• Subaru WRX (aftermarket wheel setups)
• Mazda 3 (sport and modified trims)

Because the 235/40R17 size is often tied to wider wheels and lower-profile configurations, 235/40R17 is more commonly encountered as a performance or aftermarket fitment rather than a broad OEM standard. Wheel width, offset, and clearance must be verified before use.

235/40R17 Dimensions in Inches

The 235/40R17 tire size measures approximately 9.25 inches in width, 24.4 inches in overall diameter, and has a sidewall height of about 3.70 inches.

The short 3.70-inch sidewall is the defining feature of this size. It significantly limits sidewall deformation under load, which improves steering response and lateral stability, but reduces the tire’s ability to absorb road irregularities compared to taller profiles.

235/40R17 in Inches: All Measurements

• Overall diameter: ≈24.4"
• Width: 9.25"
• Sidewall height: 3.70"
• Wheel diameter: 17"
• Circumference: ≈76.65" (≈76.6")

Most Recommended 235/40R17 Tires

Best tires in 235/40R17 size include:

• 235/40R17 all-season tires: Toyo Proxes Sport A/S+
• Summer tires 235/40R17: Nitto NT05
• Ultra-high-performance tires 235 40r17: Nitto NT01, Toyo Proxes RR

Comparison of 235/40R17 With Similar Tire Sizes

235/40R17 sits below taller 45-series alternatives and close to slightly narrower low-profile sizes. The most relevant comparisons are with 235/45R17 as the taller counterpart and 225/40R17 as a narrower alternative with a similar sidewall profile.

Difference Between 235/40R17 and 235/45R17 Tire Sizes

The 235/45R17 is taller while maintaining the same width:

• Width: identical at 235 mm
• Overall diameter: 235/45R17 is ≈0.93 inches (≈3.8%) larger than 235/40R17

This difference exceeds the ±3% threshold, meaning 235/40R17 and 235/45R17 are not directly interchangeable from a diameter standpoint. The taller 235/45R17 increases ride height and sidewall flex, which affects speedometer accuracy, gearing, and available clearance.

Difference Between 235/40R17 and 225/40R17 Tire Sizes

The 225/40R17 is narrower and slightly smaller in overall diameter:

• Width: 225/40R17 is 10 mm narrower
• Overall diameter: 225/40R17 is ≈0.32 inches (≈1.3%) smaller than 235/40R17

The difference remains within the ±3% range, so 235/40R17 and 225/40R17 are generally interchangeable from a diameter standpoint. The main change comes from reduced section width, which affects contact patch size, inner clearance relative to suspension components, and compatibility with the approved rim width range.

Before making any switch to or from 235/40R17 size, it is worth understanding how the 3% rule works and what else to check when changing this tire size.