Tire Size 235/45r18 vs 245/45r18

The main difference between tire sizes 235/45r18 and 245/45r18 is in the section width. The 245/45r18 is wider by 0.39 inches (10mm). This difference affects various performance characteristics.

Tire 1 Front View
Tire 2 Front View
Tire 1 Side View
Tire 1 Wheel
circumference 1
Tire 2 Side View
Tire 2 Wheel
/ R
/ R
Parameter235/35 R18205/40 R18Differ.
Tire Height
Section Width
Sidewall Height
Rim Size


Fitment Guide

The overall diameters of the 235/45R18 and 245/45R18 are within 1.3% of each other. According to the 3% replacement guideline, these sizes are interchangeable without clearance or speedometer issues.

Gas Mileage

With a slightly narrower tread and less rolling resistance, the 235/45R18 is marginally more fuel-efficient than the 245/45R18. This can translate to minor but measurable fuel savings over time for daily drivers.

Ground Clearance

The diameter difference between the sizes is minor at just 0.35 inches (9mm). This slightly reduces ground clearance for the 235/45R18, increasing the risks of scraping over obstacles. But the clearance difference is slight in practical terms.

235 45r18 in inches

Ride Comfort

The 245/45R18’s wider tread and taller sidewall provide a subtle improvement in ride quality over uneven roads. But both sizes deliver a comfortable ride.

Speedometer Difference

At an actual speed of 20 mph, the speedometer reads 20.27 mph for the 235/45R18 and 20 mph with the 245/45R18, a minor 0.27 mph difference.


Visually, the 4.3% wider 245/45R18 appears subtly more aggressive. For some vehicle styles, this suits the intended aesthetic over a narrower tire.

Handling & Stability

The 245/45R18’s wider contact patch provides a modest enhancement in grip and stability. But the difference is slight, with both sizes offering responsive, precise handling.

235 45r18 in inches

Noise & Vibration

The 245/45R18 runs slightly quieter thanks to its larger air chamber absorbing noise and vibration. But both transmit minimal road noise into the cabin.

Durability & Wear

With 4.3% more rubber on the road, wear rates are slightly accelerated on the 245/45R18. But the difference is slight – both deliver long tread life with even wear.

Adverse Conditions

Winter traction is similar for both sizes. The 245/45R18’s wider tread helps resist hydroplaning in heavy rain. Both perform well over loose or slippery surfaces.

Can You Use 245 Tires Instead Of 235?

Yes, you can use 245/45r18 tires instead of 235/45r18 tires. The diameter difference between the two is only 1.3%, which is less than the 3% maximum advised difference.

Just ensure the load capacity matches or exceeds your vehicle’s requirements. With only a 1.3% difference, substituting 245/45r18 tires poses no problem.

What Does 235/45r18 Mean?

The size 235/45r18 is the same as 26.3×9.3R18 when measured in inches. The tire size “235/45R18” indicates a 235 millimeters wide tire with a sidewall height comprising 45% of the width.

The “R” signifies radial construction, and the tire is designed to fit an 18-inch wheel. This specification provides key details about the tire’s dimensions, aiding in adequately selecting compatible vehicles.

What Does 245/45r18 Mean?

The tire size “245/45R18” indicates that the tire has a width of 245 millimeters, a sidewall height that is 45% of the width, radial construction (indicated by the “R”), and is compatible with an 18-inch wheel.

The tire size 245/45r18 is equal to 26.7×9.6R18 in inches. This specification provides essential information for selecting the right tire for vehicles that require these dimensions.

How Much Taller Is A 245/45r18 Tire Than A 235/45r18?

The 245/45R18 tire is 0.35 inches (9 mm) taller than the 235/45R18 tire, representing a 1.3% increase in diameter. This equates to a 1.3% difference in overall diameter between the two tires.

235/45r18 vs 245/45r18

245/45r18 vs 235/45r18

This comparison table will help you understand the differences between 235 45r18 and 245 45r18 tires.

Our Observation
Due to the minor differences across key performance parameters, the 235/45R18 and 245/45R18 represent excellent tire size options suitable for most drivers.

However, the 245/45R18 offers slightly enhanced stability and wet weather performance.

Ultimately, we recommend the 245/45R18 size based on this, provided vehicle clearance allows. But you can expect similar lifespan and overall driving experience with either size.

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