tireheight.com275/55R20 vs 285/70R17
285/70R17 is 0.9″ taller than 275/55R20 on average, going by the heights their makers list (31.9″ vs 32.9″). On paper the gap is 0.80″.
What changes
Going from 275/55R20 to 285/70R17.
Lift is half the height difference, since the axle sits at the middle of the tire. The speedometer figure assumes it was set for 275/55R20 and uses the revolutions per mile the makers publish: at an indicated 60 mph you'd be doing 61.7 mph.
Side by side
| 275/55R20 | 285/70R17 | Difference | |
|---|---|---|---|
| Listed height ″ | 31.89–32.30 | 32.70–33.15 | +0.92 |
| Size code height ″ | 31.91 | 32.71 | +0.80 |
| Height under load ″ | 31.0 | 31.8 | +0.9 |
| Width ″ | 10.83 | 11.22 | +0.39 |
| Listed width ″ | 10.8–11.2 | 11.4–11.6 | +0.3 |
| Sidewall ″ | 5.95 | 7.85 | +1.90 |
| Wheel ″ | 20 | 17 | −3 |
| Weight lb | 34.6–64.3 | 46.0–65.7 | +11.9 |
| Tread depth /32″ | 9–19 | 13–19 | +3.4 |
| Tires listed | 38 | 36 |
Tires sold in both sizes
The same model in each size, by the heights the maker lists. Averages where a model comes in several load ranges.
| Tire | 275/55R20 ″ | 285/70R17 ″ | Taller by | Heavier by |
|---|---|---|---|---|
| BFGoodrich All-Terrain T/A KO3 | 31.90 | 32.80 | +0.90″ | −0.2 lb |
| BFGoodrich Trail-Terrain T/A | 31.90 | 32.80 | +0.90″ | +0.6 lb |
| BFGoodrich Trail-Terrain T/A+ | 31.90 | 32.80 | +0.90″ | +0.0 lb |
| General Grabber A/TX | 31.90 | 32.70 | +0.80″ | +7.9 lb |
| General Grabber APT | 31.90 | 32.70 | +0.80″ | +13.8 lb |
| Michelin Defender LTX M/S 2 | 31.90 | 32.80 | +0.90″ | +12.4 lb |
| Mickey Thompson Baja Boss A/T | 32.20 | 32.90 | +0.70″ | +0.0 lb |
| Mickey Thompson Baja Legend EXP | 32.30 | 33.10 | +0.80″ | +0.0 lb |
| Toyo Open Country A/T III | 31.89 | 32.81 | +0.92″ | +6.3 lb |
| Toyo Open Country C/T | 32.13 | 32.99 | +0.87″ | +0.1 lb |
| Toyo Open Country H/T II | 31.89 | 32.76 | +0.87″ | +10.7 lb |
| Toyo Open Country M/T | 32.13 | 32.99 | +0.87″ | −0.1 lb |
| Toyo Open Country R/T Trail | 31.89 | 32.76 | +0.87″ | +11.2 lb |
Questions about 275/55R20 vs 285/70R17
How much taller is 285/70R17 than 275/55R20?
0.92″ on average, going by the heights tire makers list: 275/55R20 tires are listed at 31.89–32.30″ and 285/70R17 at 32.70–33.15″. The size codes work out to 31.91″ and 32.71″, a 0.80″ difference.
How much lift does 285/70R17 give over 275/55R20?
The tire's radius grows by 0.46″, so the axle sits about 0.46″ higher, and the top of the tread comes 0.46″ closer to the fender. 285/70R17 is also 0.39″ wider on paper, 0.20″ per side on the same wheel. Whether it fits depends on your vehicle, lift and wheel offset.
Will my speedometer be off with 285/70R17 instead of 275/55R20?
Yes. If it's set for 275/55R20, it will read about 2.8% slow: at an indicated 60 mph you'll be doing 61.7 mph. Worked out from the revolutions per mile the makers publish.
Can 285/70R17 go on the same wheel as 275/55R20?
No. 275/55R20 fits a 20-inch wheel and 285/70R17 a 17-inch wheel.