Tire RulerWhat changes when you switch to 245/65R18
- Height: +0.02″ (+0.1%), so ground clearance stays practically the same.
- Width: −0.79″ (-20 mm). Check inner clearance to the suspension and frame, and the fender liner at full lock.
- Sidewall: +0.01″. A taller sidewall rides a bit softer and protects the wheel off-road.
- Revolutions per mile: 661 → 660. Your gears act the same; at 65 mph in a 0.69 top gear with 3.73s, that’s 1,842 → 1,841 RPM.
Sizes are theoretical, from the sidewall code. The same size can differ by a few tenths of an inch between brands and tread patterns; check the maker’s spec sheet for the exact model.
Other comparisons
Frequently asked questions
How much bigger is 245/65R18 than 265/60R18?
245/65R18 is 0.02 inches (0.1%) taller and 0.79 inches narrower: 30.5" × 9.6" versus 30.5" × 10.4".
Will 245/65R18 change my speedometer?
No, the diameters are practically the same.
Can I replace 265/60R18 with 245/65R18?
Often, yes: the height difference is within the ±3% most tire shops accept. Both fit an 18" wheel; confirm the rim width, load index and clearance for your vehicle.
Do I need to regear going from 265/60R18 to 245/65R18?
Usually not for a 0.1% change. With 3.73 gears, the 245/65R18 acts like 3.73.