265/65R17 vs 33x10.50R17 — height without width
The narrow-33 route, and the only pairing in this set that adds two and a half inches of tire and essentially no casing.
33x10.50R17 is 2.44 in taller than 265/65R17 (7.97%) and 0.07 in wider. A speedometer calibrated for 265/65R17 would under-read by 7.97%.
Measured against each other
Overall diameter
30.56 in33.00 in+2.44 in (+7.97%)Section width
10.43 in / 265 mm10.50 in / 267 mm+0.07 in (+0.64%)Sidewall height
6.78 in8.00 in+1.22 inCircumference
96.0 in103.7 in+7.7 inRevolutions per mile
659.9611.2-48.7Ride height at the axle
——+1.22 inSpeedometer reading
——+7.97% under-read
| Dimension | 265/65R17 | 33x10.50R17 | Change |
|---|---|---|---|
| Overall diameter | 30.56 in | 33.00 in | +2.44 in (+7.97%) |
| Section width | 10.43 in / 265 mm | 10.50 in / 267 mm | +0.07 in (+0.64%) |
| Sidewall height | 6.78 in | 8.00 in | +1.22 in |
| Circumference | 96.0 in | 103.7 in | +7.7 in |
| Revolutions per mile | 659.9 | 611.2 | -48.7 |
| Ride height at the axle | — | — | +1.22 in |
| Speedometer reading | — | — | +7.97% under-read |
Calibrated for 265/65R17, running 33x10.50R17
- Dial reads 30
- 32.4 mph
- Dial reads 50
- 54.0 mph
- Dial reads 70
- 75.6 mph
- Odometer counts 100
- 108.0 mi covered
Change either size in the comparison tool, or see the full speed table in the speedometer error calculator.
Two and a half inches of extra diameter for seven hundredths of an inch of extra width. Nothing else in this comparison set comes close to that ratio.
The width difference is a rounding error
Seven hundredths of an inch separate them, 10.43 in from 10.50 in — 0.64%, which is less than the variation between two brands of the same size, and far less than the effect of mounting either tire on a rim half an inch wider or narrower.
Arithmetically the two tires occupy the same lateral space, to within less than a tenth of an inch. What that does or does not mean at full lock on a particular vehicle is a measurement question about that vehicle, and seven hundredths of an inch of section width is not the only thing that changes when a tire changes — the height does too, by considerably more.
Where the height comes from
Sidewall: 6.78 in to 8.00 in, an increase of 1.22 in per side. The flotation size achieves that on a narrow casing by running a very tall profile — its derived aspect ratio is 76, against the metric size's stated 65.
That is the trick the narrow 33 performs. Height is bought with profile rather than with width, which is the only way to get a 33-inch tire under a vehicle that has no room beside its wheels.
What it costs
Eight per cent, and the unusual thing about this pairing is where the eight per cent is concentrated. Almost all of it is vertical: 1.22 in of extra radius against seven hundredths of an inch of extra section width. The two dimensions people check separately move by wildly different amounts here, so a check of one tells you nothing at all about the other.
Vertical change is also the kind the cluster charges for. At a dial reading of 80 the truck is doing 86.4 — the largest reading error produced by any pairing here whose two casings sit within a tenth of an inch of each other.
Why the size is uncommon
Because the market wants wide tires. 33x10.50R17 is made by a handful of manufacturers in a handful of patterns, and it is entirely absent from some tread families that offer the 12.50 in width in four different diameters. Choosing it means accepting a much shorter list.
The wide alternative
265/65R17 against 285/70R17 reaches a slightly lower 32.71 in with 0.79 in more casing, and is the far more commonly stocked route to roughly the same place.