LIGHT TRUCK SIZE COMPARISON

265/70R17 vs 275/60R20

275/60R20 is 1.39 inches taller and 0.39 inches wider than 265/70R17 — a +4.4% change in overall diameter. Every consequence of that difference is worked out below.

Outside the 3% substitution envelope (+4.4%)

This is a modification rather than a substitution. Check clearance at full steering lock and full suspension compression, confirm the load rating meets the placard, and expect the speedometer to read low by about 4.4% unless it can be recalibrated for the new size.

20"
Overall diameter+1.39"31.61" → 32.99"
Ride height at the axle+0.69"Half the diameter change
Section width+0.39"10.43" → 10.83"
Sidewall height−0.81"7.3" → 6.5"
True speed at indicated 6062.6 mphSpeedometer reads low
Odometer per 1,000 miles+44 miReal distance against indicated

Want to try other sizes against these? Open this comparison in the interactive tool.

WHAT THIS SWAP IS

This is a plus-size: bigger wheel, shorter sidewall

Going from 265/70R17 to 275/60R20 moves the rim from 17 inches to 20 and drops the aspect ratio from 70 to 60. That is the classic plus-size pattern, and the intention behind it is usually appearance and steering response rather than clearance.

The sidewall shrinks from 7.3 inches to 6.5 — 0.81 inches less rubber between the rim and the road. Less sidewall flex sharpens turn-in and makes the steering feel more immediate, which is the point.

The trade is real and worth stating plainly. A shorter sidewall transmits more of the road surface into the cabin, and it leaves the rim far more exposed to pothole damage. Replacement cost also rises, because both the larger wheel and the lower-profile tire are more expensive than what they replace.

EVERY MEASUREMENT

265/70R17 and 275/60R20 measured against each other

Both sizes reduced to the same units. The diameter row is the one that drives everything else on this page — ride height, gearing, speedometer accuracy and odometer readings all follow from it.

Measurement265/70R17275/60R20Difference
Overall diameter31.61"32.99"+1.39" (+4.4%)
Section width10.43" (265 mm)10.83" (275 mm)+0.39"
Sidewall height7.3"6.5"−0.81"
Rim diameter17"20"+3"
Circumference99.29"103.65"+4.35"
Revolutions per mile638611−27
Ride height at axleBaseline+0.69"+0.69"
SPEEDOMETER EFFECT

What the dial shows against how fast you are going

Your speedometer was calibrated to 265/70R17, which turns about 638 times per mile. Fit 275/60R20 at about 611 revolutions per mile and the same wheel speed now represents a greater road speed than the instrument assumes. The error is 4.4% at every speed, so it grows in absolute terms the faster you go.

Speedometer readsYou are actually doingDifference
30 mph31.3 mph+1.3 mph
45 mph47 mph+2 mph
60 mph62.6 mph+2.6 mph
75 mph78.3 mph+3.3 mph

Over distance the same proportion applies to the odometer. Every indicated 1,000 miles on 275/60R20 is really about 1044 miles covered — worth knowing on a leased vehicle, where recorded mileage and real mileage drift apart.

BEFORE YOU ORDER

What this particular change asks you to check

  • Section width grows by 0.39 inches, so the tire sits closer to the strut and the inner liner on both sides.
  • Overall height grows by 1.39 inches, of which 0.69 inches goes upward into the arch — check at full lock and full compression.
  • The rim diameter changes from 17 inches to 20 inches, so this swap needs different wheels as well as different tires.
  • Speedometer error of 4.4% — check whether your vehicle supports recalibrating for a new tire size.
  • Confirm the load index on 275/60R20meets or exceeds the figure on the vehicle's tire placard, particularly if the vehicle tows or carries load.
  • On all-wheel-drive and four-wheel-drive vehicles, change all four together — mismatched rolling circumferences load the differentials and transfer case continuously.
COMMON QUESTIONS

265/70R17 vs 275/60R20 FAQ

Is 275/60R20 bigger than 265/70R17?+

275/60R20 measures 32.99 inches in overall diameter against 31.61 inches for 265/70R17. That makes it 1.39 inches taller, a change of +4.4%. It is also 0.39 inches wider in section width.

Will 275/60R20 fit in place of 265/70R17?+

The diameter change is +4.4%, which is outside the 3% envelope usually treated as a routine substitution. Treat this as a modification: verify clearance at full steering lock and full suspension compression, confirm the load rating meets the vehicle placard, and expect the speedometer to read incorrectly unless it can be recalibrated.

How much lift does 275/60R20 give over 265/70R17?+

0.69 inches at the axle — half the diameter difference. The other half of the change goes upward into the wheel arch, which is where fitment problems usually appear.

How far off will my speedometer be?+

The speedometer will read low by about 4.4%. At an indicated 60 mph you would actually be travelling about 62.6 mph, and every indicated 1,000 miles would really be about 1044.

Do I need to regear for 275/60R20?+

A +4.4% change shifts the effective gearing noticeably. To restore the original engine speed you would multiply the current axle ratio by 1.044. Whether that is worth doing depends on how the vehicle is used — towing and heavily loaded driving make the case sooner than commuting does.

What is the revolutions-per-mile difference?+

265/70R17 turns about 638 times per mile and 275/60R20 about 611 — a difference of −27 revolutions. That figure is what the speedometer and odometer are calibrated against, which is why both readings shift.

!

These are nominal figures. Every number above is calculated from the marked size. Real tires vary from nominal by a few millimetres between manufacturers, and by more as tread wears or pressure changes. Use this to plan and to check a quote — measure the actual tire before committing to a tight fitment.

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