665/21R30 Tire Size Specifications
This tire size 665/21R30 fits 0 vehicles in our database.
Everything to know about the 665/21R30 tire size
Size geometry
A 665/21R30 tire has a 665mm section width and a 21% aspect ratio, mounted on a 30-inch rim. Sidewall height works out to 139.7mm (5.50") and overall outside diameter is 1041.3mm (41.00"). At highway speed the tire completes about 306 revolutions per kilometre â your speedometer and odometer were calibrated against this number.
Direct substitute sizes
If 665/21R30 is unavailable, the closest same-diameter substitutes on the same rim are 655/21R30 and 675/21R30. Both keep your speedometer reading within 1% â safe for daily use, ABS, and stability control. Always verify load and speed ratings before swapping.
Plus / minus sizing options
For a 665/21R30 you can upsize to 675/19R31 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 655/23R29 (minus-one) for a softer ride or winter setup. Both stay inside the Âą3% diameter tolerance that ABS and TPMS systems expect.
Vehicle compatibility
0 vehicles in our database run the 665/21R30 tire size from the factory. Aftermarket fitment depends on rim width, offset, and clearance â match these specs to your wheel before purchasing tires.
Vehicles Using 665/21R30
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