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Tire size

255/65R18 tire size: dimensions explained

Factory size on the Ford Ranger. Below are the dimensions calculated from the size marking itself. Your vehicle's correct size, load index and speed rating are on the placard in the driver's door jamb; check it before buying.

MeasurementMetricImperial
Section width255 mm10.04 in
Sidewall height165.8 mm6.53 in
Overall diameter788.7 mm31.05 in
Wheel diameter457.2 mm18 in
Circumference2479 mm97.6 in
Revolutions per mile650

Calculated values: diameter = wheel + 2 × (width × aspect ratio). Real tires vary slightly by brand and model.

Reading the marking

255 is the section width in millimetres, 65 is the sidewall height as a percentage of that width, R means radial construction, and 18 is the wheel diameter in inches. A passenger (P or Euro-metric) tire and an LT tire in the same size are not interchangeable without checking load requirements.

Compare 255/65R18 with another size →

255/65R18 tires at Tire Rack

All-season

TireLoad/speedPrice per tire
Radar Dimax AS-8
Grand Touring All-Season		XL 115H$151.95View at Tire Rack
Michelin Primacy A/S
Standard Touring All-Season		111H$173.59View at Tire Rack

Highway / touring

TireLoad/speedPrice per tire
Vredestein Pinza HT
Highway All-Season		111T$136.04View at Tire Rack
Yokohama Geolandar CV G058
Crossover/SUV Touring All-Season		111H$144.04View at Tire Rack

All-terrain

TireLoad/speedPrice per tire
Goodyear Wrangler Territory AT
On-Road All-Terrain		111T$167.47View at Tire Rack
Radar Renegade A/T Trail
On-Road All-Terrain		XL 115H$169.92View at Tire Rack

Winter

TireLoad/speedPrice per tire
Goodyear WinterCommand (SUV)
Light Truck/SUV Studdable Snow Truck		111S$145.65View at Tire Rack
Firestone Winterforce 2 UV
Light Truck/SUV Studdable Snow Truck		109S$196.99View at Tire Rack

Showing the lowest-priced in-stock options in each category from 63 255/65R18 tires in Tire Rack's feed, sorted by price only. We don't rank by commission. Match or exceed the load index and speed rating on your placard.

Affiliate links: if you buy through a Tire Rack link, RightTread may earn a commission through CJ. It doesn't change your price. Prices are Tire Rack's per-tire prices from Tire Rack's product feed as of Nov 7, 2026, 9:19 PM PT. Prices change, so confirm on Tire Rack before you buy. Disclosure

Other sizes