275/55R19 vs 285/65R17
285/65R17 has an overall diameter of 802.3 mm (31.59") compared with 785.1 mm (30.91") for 275/55R19, a difference of +17.2 mm (+2.19 %). The sidewall changes by +34.0 mm, section width by +10 mm and ride height by +8.6 mm. Using the ETRTO rolling circumference, 275/55R19 turns 418 times per kilometre and 285/65R17 turns 409 times. With 285/65R17 fitted to a car calibrated for 275/55R19, an indicated 100 km/h is a true 102.2 km/h, and the odometer records 97.9 km for every 100 km driven. This is close to the commonly quoted 3 % tolerance, so check clearance and local rules.
Full comparison
| Measurement | 275/55R19 | 285/65R17 | Difference |
|---|---|---|---|
| Section width | 275 mm | 285 mm | +10 mm |
| Sidewall height | 151.3 mm | 185.3 mm | +34.0 mm |
| Rim diameter | 19" | 17" | -2.0" |
| Overall diameter | 785.1 mm (30.91") | 802.3 mm (31.59") | +17.2 mm (+2.19 %) |
| Static circumference | 2466 mm | 2520 mm | +54 mm |
| Rolling circumference (ETRTO) | 2395 mm | 2447 mm | +52 mm |
| Revs per km | 418 | 409 | -9 |
| Ride height | +8.6 mm | ||
| Inch equivalent | 30.9×10.8R19 | 31.6×11.2R17 | |
| Approved rim widths (approx.) | 7.5″–9.5″ | 8″–9.5″ |
Speedometer error
| Speedo reads | 40 | 50 | 60 | 80 | 100 | 110 |
|---|---|---|---|---|---|---|
| Actual speed (km/h) | 40.9 | 51.1 | 61.3 | 81.8 | 102.2 | 112.4 |
| Error (km/h) | +0.9 | +1.1 | +1.3 | +1.8 | +2.2 | +2.4 |
Assumes the speedo was accurate on 275/55R19. Odometer records 97.9 km for every 100 km actually driven.
- The 285/65R17 is 17.2 mm (2.19 %) larger in diameter, so your speedo will read low and your odometer will under-record distance.
- Section width changes by +10 mm. Check guard, strut and inner-arch clearance and that the rim width is within the approved range for the new tyre.
- Rim diameter changes from 19" to 17", so new wheels are required.
Is 285/65R17 legal in Australia? Needs certification
| Overall diameter (VSB 14 LS 4.2.4) 285/65R17 is 17.2 mm larger than 275/55R19; the limit without certification for a passenger car (MA/MB) is +15 mm. Larger increases need an approved signatory / engineering certificate (modification code LS or state equivalent) and may not be permitted at all. | Cert. |
| Speedometer (ADR 18/03) A larger tyre makes the speedo read lower: at an indicated 100 km/h you would be doing 102.2 km/h. ADR 18 requires the speedo never to read below true speed, but factory speedos typically over-read by 2-6 %, so a 2.2 % increase is usually absorbed. Verify with a GPS speed app after fitting. | Verify |
| Load index (tyre placard / ADR 42) Enter the placard load index and the replacement tyre load index to check. | ? |
| Speed rating (tyre placard / ADR 42) Enter the placard speed rating and the replacement tyre speed rating to check. | ? |
Frequently asked
Can I fit 285/65R17 instead of 275/55R19?
Overall diameter changes by +17.2 mm (+2.19 %). That is close to the 3 % rule of thumb; it may fit, but check guard, strut and brake clearance and your local rules. In Australia VSB 14 allows up to +15 mm for passenger cars and +50 mm for 4WDs/goods vehicles without certification.
How much will my speedo be out with 285/65R17?
Your speedo will read low by about 2.19 %. At an indicated 100 km/h you would actually be travelling 102.2 km/h, and at 110 km/h about 112.4 km/h.
What is the rolling circumference of 285/65R17?
Static circumference is 2520 mm; the ETRTO rolling circumference under load is about 2447 mm, which is 409 revolutions per kilometre.
285/65R17 in inches
285/65R17 is approximately 31.6×11.2R17: 31.6" tall, 11.2" wide, on a 17" rim, with a 7.3" sidewall.
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