Tire RulerWhat changes when you switch to 255/70R16
- Height: +0.18″ (+0.6%), so ground clearance at the axle goes up 0.09″.
- Width: +0.79″ (20 mm). Check inner clearance to the suspension and frame, and the fender liner at full lock.
- Sidewall: +0.09″. A taller sidewall rides a bit softer and protects the wheel off-road.
- Revolutions per mile: 675 → 671. Your gears act about 0.6% taller; at 65 mph in a 0.69 top gear with 3.73s, that’s 1,882 → 1,871 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 255/70R16 than 235/75R16?
255/70R16 is 0.18 inches (0.6%) taller and 0.79 inches wider: 30.1" × 10.0" versus 29.9" × 9.3".
Will 255/70R16 change my speedometer?
Yes, by 0.6%. Going from 235/75R16 to 255/70R16, an indicated 60 mph is about 60.4 mph.
Can I replace 235/75R16 with 255/70R16?
Often, yes: the height difference is within the ±3% most tire shops accept. Both fit a 16" wheel; confirm the rim width, load index and clearance for your vehicle.
Do I need to regear going from 235/75R16 to 255/70R16?
Usually not for a 0.6% change. With 3.73 gears, the 255/70R16 acts like 3.71.