Tire Size Box

295/60R18 vs 295/70R18

295/70R18 compared with 295/60R18

+7.3% diameter, 0.0" width

295/70R18 is 34.26" tall vs 31.94". More than the 3% rule of thumb, so check carefully before switching.

31.9"18" rim7.0"11.6" wide
295/60R18 (solid) compared with 295/70R18 (dashed outline), drawn to scale

With 295/70R18 tires, when your speedometer says 60 mph you are really going

64.4 mph

295/70R18 is +2.32 inches (+7.3%) in overall diameter. That is more than the 3% most shops and makers recommend.

295/60R18295/70R18Difference%
Overall diameter31.94"34.26"+2.32"+7.3%
Section width11.61"11.61"0.00"0.0%
Sidewall height6.97"8.13"+1.16"+16.7%
Circumference100.33"107.63"+7.30"+7.3%
Revolutions per mile631.5588.7−42.8−6.8%

Speedometer difference

If your vehicle came with 295/60R18 and you fit 295/70R18, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.5 mph+1.5 mph
30 mph32.2 mph+2.2 mph
40 mph42.9 mph+2.9 mph
50 mph53.6 mph+3.6 mph
60 mph64.4 mph+4.4 mph
65 mph69.7 mph+4.7 mph
70 mph75.1 mph+5.1 mph
75 mph80.5 mph+5.5 mph
80 mph85.8 mph+5.8 mph

Each size on its own

Questions

Which is bigger, 295/60R18 or 295/70R18?
295/70R18 is taller by 2.32 inches (34.26" vs 31.94"). 295/60R18 is the same width.
Can I replace 295/60R18 with 295/70R18?
It is not recommended without checking carefully. The diameter difference is +7.3%, 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 295/70R18 change my speedometer?
When your speedometer reads 60 mph with 295/70R18 fitted (calibrated for 295/60R18), your real speed is 64.4 mph. Your odometer will under-count miles by about 7.3%.
Will 295/70R18 lift my vehicle?
Ride height changes by half the diameter difference: +1.16 inches of ground clearance at the axle.

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