245/40R20 vs 245/45R20

245/40R20 vs 245/45R20: Comparision Size Chart


245/40R20 (Tire 1)245/45R20 (Tire 2)Difference
Tire Size In Inches27.7X9.6R2028.7X9.6R20
Diameter27.72"704 mm28.68"728.5 mm3.48%
Tread Width9.6245 mm9.6"245 mm0%
Rim Diameter20"508 mm20"508 mm0%
Sidewall Height3.86"98 mm4.34"110.25 mm12.5%
Circumference87.08"2211.68 mm90.1"2211.68 mm3.48%
Revs/Mile727.61 Revs/Mile703.22 Revs/Mile-24.39
Revs/Kilometer452.12 Revs/Mile436.96 Revs/Mile-15.16
Tire 1 Front View
9.6"
27.72"
Tire 2 Front View
9.6"
28.68"
Tire 1 Side View
Tire 1 Wheel
Circumference 1
87.08"
20"
3.86"
727.61 Revs/Mile
Tire 2 Side View
Tire 2 Wheel
Circumference 2
90.1"
20"
4.34"
703.22 Revs/Mile

Speedometer Error

245/40R20 (Mph)245/45R20 (Mph)
2020.7
3536.22
5051.74
6567.26
8082.78
9093.13
100103.48

245/45R20 vs 245/40R20: Gas Mileage & Performance Comparison

* Below is a comparison table. Assuming 2 tires of the same manufacturer, material and tested on the same road conditions.

245/40R20245/45R20
Wet/Snowy RoadsBetter TractionReduced Traction
Rough TerrainReduced StabilitySmoother Ride
Handling/SteeringLess ResponsiveLess Responsive
Gas MileageGoodBetter
Road NoiseQuieterQuieter
CostLess ExpensiveMore Expensive

Can You Replace The 245/40R20 With The 245/45R20?

No, both tires have the same rim diameter, but the 245/45R20 has a bigger overall diameter than the 245/40R20 which is 3.36% (0.96-inch).

When you want to replace a different tire size, as a rule, for the rim diameter, you will need to be sure that your tires and rims are an exact match, e.g. a 245/40R20 tire will only fit on a 20″ diameter rim.

You Can check our tools and charts below to find your size:

*Disclaimer: The information provided on the tire size is for general informational purposes only. We recommend that you consult a certified tire specialist or National Highway Traffic Safety Administration (NHTSA) sets specific guidelines for tires used on vehicles.


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Jamie Hicks

Sullivan Kane

Tire Technician at TireSizesCalculator

Sullivan is a Tire Technician specializing in tire repair at TireSizesCalculator. With over 6 years of experience in the industry, Sullivan has become an expert in tire repair, maintenance & installation.


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