What is the diameter difference between 265/70R16 and 265/65R17?

265/70R16 has an overall diameter of 30.61 inches (777 mm). 265/65R17 is 30.56 inches (776 mm). That's a 0.04 inch (1 mm) difference — 265/65R17 is shorter.

Will 265/65R17 cause speedometer error on a car fitted with 265/70R16?

Swapping 265/70R16 for 265/65R17 produces a speedometer error of about 0.1%. Your speedometer will read higher than your actual speed — a 60 mph indicated reading is really 59.9 mph. Anything under 3% is usually acceptable without recalibration.

How many revolutions per mile does each size do?

265/70R16 turns 659 revs per mile. 265/65R17 turns 660 revs per mile. Taller tyres turn fewer times per mile, which lowers effective final-drive ratio.

What's the sidewall height difference?

265/70R16 has a sidewall of 186 mm (7.3 in). 265/65R17 sidewall is 172 mm (6.78 in). Lower-profile sidewalls give sharper steering response but less bump compliance.

Is 265/65R17 a safe plus-size upgrade from 265/70R16?

A plus-size upgrade is considered safe when overall diameter stays within ±3% — here the difference is 0.1%. This swap is within the typical safe range; speedometer and ABS calibration should remain close to factory.

Tire size comparison

265/70R16 vs 265/65R17

Overall diameter, sidewall, revs per mile, and speedometer error — 265/70R16 is the taller tire, with a 0.1% speedo delta when swapping.

265/70R16

30.61in

777 mm overall diameter

265/65R17

30.56in

776 mm overall diameter

Diameter Δ

0.04 in

Speedo error

0.1%

265/70R16 revs/mi

659

265/65R17 revs/mi

660

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	265/70R16	265/65R17
Section width	265 mm	265 mm
Aspect ratio	70	65
Wheel diameter	16″	17″
Sidewall height	186 mm	172 mm
Overall diameter	30.61 in (777 mm)	30.56 in (776 mm)
Circumference	96.15 in	96.02 in
Revolutions / mile	659	660

Other comparisons for these sizes

265/70R17 vs 265/65R17

FAQ

Frequently asked

What is the diameter difference between 265/70R16 and 265/65R17?: 265/70R16 has an overall diameter of 30.61 inches (777 mm). 265/65R17 is 30.56 inches (776 mm). That's a 0.04 inch (1 mm) difference — 265/65R17 is shorter.
Will 265/65R17 cause speedometer error on a car fitted with 265/70R16?: Swapping 265/70R16 for 265/65R17 produces a speedometer error of about 0.1%. Your speedometer will read higher than your actual speed — a 60 mph indicated reading is really 59.9 mph. Anything under 3% is usually acceptable without recalibration.
How many revolutions per mile does each size do?: 265/70R16 turns 659 revs per mile. 265/65R17 turns 660 revs per mile. Taller tyres turn fewer times per mile, which lowers effective final-drive ratio.
What's the sidewall height difference?: 265/70R16 has a sidewall of 186 mm (7.3 in). 265/65R17 sidewall is 172 mm (6.78 in). Lower-profile sidewalls give sharper steering response but less bump compliance.
Is 265/65R17 a safe plus-size upgrade from 265/70R16?: A plus-size upgrade is considered safe when overall diameter stays within ±3% — here the difference is 0.1%. This swap is within the typical safe range; speedometer and ABS calibration should remain close to factory.