Tire RulerWhat changes when you switch to 33x12.50R17
- Height: +0.29″ (+0.9%), so ground clearance at the axle goes up 0.15″.
- Width: +1.28″ (33 mm). Check inner clearance to the suspension and frame, and the fender liner at full lock.
- Sidewall: +0.15″. A taller sidewall rides a bit softer and protects the wheel off-road.
- Revolutions per mile: 617 → 611. Your gears act about 0.9% taller; at 65 mph in a 0.69 top gear with 3.73s, that’s 1,719 → 1,704 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.
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Frequently asked questions
How much bigger is 33x12.50R17 than 285/70R17?
33x12.50R17 is 0.29 inches (0.9%) taller and 1.28 inches wider: 33.0" × 12.5" versus 32.7" × 11.2".
Will 33x12.50R17 change my speedometer?
Yes, by 0.9%. Going from 285/70R17 to 33x12.50R17, an indicated 60 mph is about 60.5 mph.
Can I replace 285/70R17 with 33x12.50R17?
Often, yes: the height difference is within the ±3% most tire shops accept. Both fit a 17" wheel; confirm the rim width, load index and clearance for your vehicle.
Do I need to regear going from 285/70R17 to 33x12.50R17?
Usually not for a 0.9% change. With 3.73 gears, the 33x12.50R17 acts like 3.70.