Tire Size Box

215/30R20 vs 215/35R20

215/35R20 compared with 215/30R20

+3.4% diameter, 0.0" width

215/35R20 is 25.93" tall vs 25.08". More than the 3% rule of thumb, so check carefully before switching.

25.1"20" rim2.5"8.5" wide
215/30R20 (solid) compared with 215/35R20 (dashed outline), drawn to scale

With 215/35R20 tires, when your speedometer says 60 mph you are really going

62.0 mph

215/35R20 is +0.85 inches (+3.4%) in overall diameter. That is more than the 3% most shops and makers recommend.

215/30R20215/35R20Difference%
Overall diameter25.08"25.93"+0.85"+3.4%
Section width8.46"8.46"0.00"0.0%
Sidewall height2.54"2.96"+0.42"+16.7%
Circumference78.79"81.45"+2.66"+3.4%
Revolutions per mile804.2777.9−26.3−3.3%

Speedometer difference

If your vehicle came with 215/30R20 and you fit 215/35R20, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.7 mph+0.7 mph
30 mph31.0 mph+1.0 mph
40 mph41.4 mph+1.4 mph
50 mph51.7 mph+1.7 mph
60 mph62.0 mph+2.0 mph
65 mph67.2 mph+2.2 mph
70 mph72.4 mph+2.4 mph
75 mph77.5 mph+2.5 mph
80 mph82.7 mph+2.7 mph

Each size on its own

Questions

Which is bigger, 215/30R20 or 215/35R20?
215/35R20 is taller by 0.85 inches (25.93" vs 25.08"). 215/30R20 is the same width.
Can I replace 215/30R20 with 215/35R20?
It is not recommended without checking carefully. The diameter difference is +3.4%, more than the 3% most shops and makers allow. It will throw off the speedometer and may affect ABS, stability control and clearance.
How much will 215/35R20 change my speedometer?
When your speedometer reads 60 mph with 215/35R20 fitted (calibrated for 215/30R20), your real speed is 62.0 mph. Your odometer will under-count miles by about 3.4%.
Will 215/35R20 lift my vehicle?
Ride height changes by half the diameter difference: +0.42 inches of ground clearance at the axle.

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