245/60R20 vs 265/70R17 — three inches of wheel, same height
A wheel swap disguised as a tire comparison, and 1.52 in of sidewall that appears from nowhere.
265/70R17 is 0.03 in taller than 245/60R20 (0.10%) and 0.79 in wider. A speedometer calibrated for 245/60R20 would under-read by 0.10%.
Measured against each other
Overall diameter
31.57 in31.61 in+0.03 in (+0.10%)Section width
9.65 in / 245 mm10.43 in / 265 mm+0.79 in (+8.16%)Sidewall height
5.79 in7.30 in+1.52 inCircumference
99.2 in99.3 in+0.1 inRevolutions per mile
638.7638.1-0.6Ride height at the axle
——+0.02 inSpeedometer reading
——+0.10% under-read
| Dimension | 245/60R20 | 265/70R17 | Change |
|---|---|---|---|
| Overall diameter | 31.57 in | 31.61 in | +0.03 in (+0.10%) |
| Section width | 9.65 in / 245 mm | 10.43 in / 265 mm | +0.79 in (+8.16%) |
| Sidewall height | 5.79 in | 7.30 in | +1.52 in |
| Circumference | 99.2 in | 99.3 in | +0.1 in |
| Revolutions per mile | 638.7 | 638.1 | -0.6 |
| Ride height at the axle | — | — | +0.02 in |
| Speedometer reading | — | — | +0.10% under-read |
Calibrated for 245/60R20, running 265/70R17
- Dial reads 30
- 30.0 mph
- Dial reads 50
- 50.0 mph
- Dial reads 70
- 70.1 mph
- Odometer counts 100
- 100.1 mi covered
Change either size in the comparison tool, or see the full speed table in the speedometer error calculator.
Three wheel sizes apart, and the two assemblies are the same height. Everything interesting here is in what is wrapped around the wheel rather than in how far off the ground the vehicle sits.
The trade, in one line
The 17-inch fitment carries 7.30 in of sidewall. The 20-inch fitment carries 5.79 in. That is 1.52 in of difference per side — three inches of wheel diameter, absorbed exactly.
Overall diameter comes out at 31.57 in and 31.61 in respectively. A gap of 0.03 in, which is 0.10%, which is nothing.
Why the same vehicle is sold both ways
Because they are aimed at different buyers and both roll identically, so a single speedometer calibration, a single set of ABS constants and a single axle ratio serve the whole model range. The Limited gets the 20-inch wheel and the low-profile tire; the off-road trims get the 17 and the tall sidewall. Nothing in the driveline has to know which one is fitted.
What actually differs
- Section width: 9.65 in against 10.43 in — the 17-inch fitment is 0.79 in wider
- Sidewall: 5.79 in against 7.30 in
- Available tread: 265/70R17 is one of the most heavily stocked light-truck sizes in North America and is offered in every category including mud-terrain; 245/60R20 is a much narrower list, weighted toward highway patterns
That third point is usually what the decision comes down to, and it is not a geometric argument at all.
Swapping between them
Since the rolling diameters match, moving from one factory wheel package to the other requires no recalibration whatsoever. What it does require is that the 17-inch wheel clears the brakes, which is a hard mechanical question about a specific vehicle and is not addressed by any figure above.
The cost side
A 20-inch wheel and a 5.79 in sidewall is the more expensive assembly to replace after damage, and it is the more expensive tire to buy in most patterns. The 17-inch package is cheaper on both counts and heavier on neither by any consistent margin, since the wheel and the tire pull in opposite directions on weight.
The upgrade from either
From the 17-inch package, the common next size is 285/70R17, at 1.10 in taller. From the 20-inch package the options are thinner on the ground, which is another reason owners planning larger tires tend to start by acquiring the smaller wheels.