What is the diameter difference between 175/65R14 and 185/65R14?

175/65R14 has an overall diameter of 22.96 inches (583 mm). 185/65R14 is 23.47 inches (596 mm). That's a 0.51 inch (13 mm) difference — 185/65R14 is taller.

Will 185/65R14 cause speedometer error on a car fitted with 175/65R14?

Swapping 175/65R14 for 185/65R14 produces a speedometer error of about 2.2%. Your speedometer will read lower than your actual speed — a 60 mph indicated reading is really 61.3 mph. Anything under 3% is usually acceptable without recalibration.

How many revolutions per mile does each size do?

175/65R14 turns 879 revs per mile. 185/65R14 turns 859 revs per mile. Taller tyres turn fewer times per mile, which lowers effective final-drive ratio.

What's the sidewall height difference?

175/65R14 has a sidewall of 114 mm (4.48 in). 185/65R14 sidewall is 120 mm (4.73 in). Lower-profile sidewalls give sharper steering response but less bump compliance.

Is 185/65R14 a safe plus-size upgrade from 175/65R14?

A plus-size upgrade is considered safe when overall diameter stays within ±3% — here the difference is 2.2%. This swap is within the typical safe range; speedometer and ABS calibration should remain close to factory.

Tire size comparison

175/65R14 vs 185/65R14

Overall diameter, sidewall, revs per mile, and speedometer error — 185/65R14 is the taller tire, with a 2.2% speedo delta when swapping.

175/65R14

22.96in

583 mm overall diameter

185/65R14

23.47in

596 mm overall diameter

Diameter Δ

0.51 in

Speedo error

2.2%

175/65R14 revs/mi

879

185/65R14 revs/mi

859

Within the ±3% overall-diameter band usually considered safe for plus-sizing — speedometer and ABS calibration should stay close to factory.

Full spec

Side by side

Metric	175/65R14	185/65R14
Section width	175 mm	185 mm
Aspect ratio	65	65
Wheel diameter	14″	14″
Sidewall height	114 mm	120 mm
Overall diameter	22.96 in (583 mm)	23.47 in (596 mm)
Circumference	72.12 in	73.73 in
Revolutions / mile	879	859

Other comparisons for these sizes

175/65R14 vs 185/60R15 185/65R14 vs 195/60R15 185/65R14 vs 185/60R15 185/65R14 vs 205/55R16

FAQ

Frequently asked

What is the diameter difference between 175/65R14 and 185/65R14?: 175/65R14 has an overall diameter of 22.96 inches (583 mm). 185/65R14 is 23.47 inches (596 mm). That's a 0.51 inch (13 mm) difference — 185/65R14 is taller.
Will 185/65R14 cause speedometer error on a car fitted with 175/65R14?: Swapping 175/65R14 for 185/65R14 produces a speedometer error of about 2.2%. Your speedometer will read lower than your actual speed — a 60 mph indicated reading is really 61.3 mph. Anything under 3% is usually acceptable without recalibration.
How many revolutions per mile does each size do?: 175/65R14 turns 879 revs per mile. 185/65R14 turns 859 revs per mile. Taller tyres turn fewer times per mile, which lowers effective final-drive ratio.
What's the sidewall height difference?: 175/65R14 has a sidewall of 114 mm (4.48 in). 185/65R14 sidewall is 120 mm (4.73 in). Lower-profile sidewalls give sharper steering response but less bump compliance.
Is 185/65R14 a safe plus-size upgrade from 175/65R14?: A plus-size upgrade is considered safe when overall diameter stays within ±3% — here the difference is 2.2%. This swap is within the typical safe range; speedometer and ABS calibration should remain close to factory.