135/90R17 Tire Size

All You Need to Know About 135/90R17 Tires

The T135/90R17 tire belongs to the temporary spare category, where dimensions are engineered to approximate the rolling diameter of full-size tires more closely than smaller spare formats such as T125/70R17.

135/90R17 specifies a tire that is 135 mm wide, with a 90% aspect ratio and a 17-inch wheel diameter, resulting in an overall diameter of ≈26.6 inches and a sidewall height of ≈4.8 inches.

Compared to 135/80R17, the 135/90R17 increases sidewall height and total diameter. This brings the rolling circumference closer to that of standard passenger tires, which directly reduces rotational speed differences when the spare is installed.

Despite the closer diameter match,135/90R17 remains a temporary-use tire. It is designed for short-distance operation under restricted speed conditions, not continuous driving.

135/90R17 Size Quick Specs

• Approved rim width range: 3.5-5.0"
• Overall diameter: ≈26.6"
• Section width: 135 mm
• Sidewall height: 121.5 mm
• Fits: 17-inch wheels (temporary spare applications)
• Typical inflation pressure: ≈60 PSI

Note: The calculated overall diameter of 135/90R17 is ≈26.6 inches. Actual values typically vary within ±0.1-0.2 inches, depending on tire construction.

135/90R17 Dimensions in Inches

The 135/90R17 tire is approximately 5.3 inches in width, 26.6 inches tall overall, and has a sidewall height of about 4.8 inches.

At ≈26.6 inches in diameter, the 135/90R17 size circumference is ≈83.5 inches, which determines the distance traveled per full rotation. This places the 135/90R17 size very close to many full-size 17-inch passenger tires.

135/90R17 in Inches: All Measurements

• Overall diameter: ≈26.6"
• Width: ≈5.3"
• Sidewall height: ≈4.8"
• Wheel diameter: 17"
• Circumference: ≈83.5"

Circumference Difference of 135/90R17 vs Full-Size Tires

A 135/90R17 spare has a circumference of ≈83.5 inches, compared to ≈82-90 inches for most passenger vehicles equipped with 17-inch wheels.

This results in a rolling difference typically within 0-6.5 inches per rotation, or about 0-8%, depending on the original tire size.

Because 135/90R17 size closely approaches standard tire diameters, it produces lower rotational mismatch than smaller spare sizes such as 125/70R17 or 135/80R17. Reduced mismatch directly lowers the amount of correction required from the differential during operation.

135/90R17 Axle Placement Requirements

The 135/90R17 temporary spare should be installed away from the driven axle when possible.

On front-wheel-drive vehicles, placing the 135/90R17 spare on the rear axle minimizes continuous differential compensation. On rear-wheel-drive vehicles, installing it on the front axle serves the same purpose.

Although the ≈26.6-inch diameter reduces mismatch, it does not eliminate it. Continuous differences in rotational speed still occur, which is why axle placement remains a critical factor.

135/90R17 PSI Requirements

A 135/90R17 temporary spare typically requires inflation to approximately 60 PSI.

The narrow 135 mm width of the 135/90R17 tire size limits the contact patch. Higher internal pressure is necessary to support vehicle load and maintain structural integrity.

If 135/90R17 pressure drops below specification, the tire cannot maintain its load capacity, increasing sidewall flex and heat buildup. Maintaining correct inflation is therefore essential for safe temporary operation.

Most Recommended 135/90R17 Tires

Best tires in 135/90R17 size include: Continental Spare Tire, Kumho 121