tireheight.com305/65R17 vs 285/70R17
305/65R17 and 285/70R17 are about the same height: 32.7″ and 32.9″ on average as listed by their makers (32.61″ and 32.71″ on paper).
What changes
Going from 305/65R17 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 305/65R17 and uses the revolutions per mile the makers publish: at an indicated 60 mph you'd be doing 60.5 mph.
Side by side
| 305/65R17 | 285/70R17 | Difference | |
|---|---|---|---|
| Listed height ″ | 32.60–32.90 | 32.70–33.15 | +0.12 |
| Size code height ″ | 32.61 | 32.71 | +0.10 |
| Height under load ″ | 31.6 | 31.8 | +0.2 |
| Width ″ | 12.01 | 11.22 | −0.79 |
| Listed width ″ | 12.0–12.3 | 11.4–11.6 | −0.7 |
| Sidewall ″ | 7.81 | 7.85 | +0.05 |
| Wheel ″ | 17 | 17 | same |
| Weight lb | 58.5–67.0 | 46.0–65.7 | −6.6 |
| Tread depth /32″ | 15–21 | 13–19 | −2.2 |
| Tires listed | 5 | 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 | 305/65R17 ″ | 285/70R17 ″ | Taller by | Heavier by |
|---|---|---|---|---|
| BFGoodrich All-Terrain T/A KO2 | 32.60 | 32.80 | +0.20″ | −7.7 lb |
| Mickey Thompson Baja Boss A/T | 32.80 | 32.90 | +0.10″ | −11.5 lb |
| Mickey Thompson Baja Boss M/T | 32.70 | 33.00 | +0.30″ | −4.0 lb |
| Mickey Thompson Baja Legend EXP | 32.90 | 33.10 | +0.20″ | −3.0 lb |
| Mickey Thompson Baja Legend MTZ | 32.70 | 33.00 | +0.30″ | −2.0 lb |
Questions about 305/65R17 vs 285/70R17
How much taller is 285/70R17 than 305/65R17?
0.12″ on average, going by the heights tire makers list: 305/65R17 tires are listed at 32.60–32.90″ and 285/70R17 at 32.70–33.15″. The size codes work out to 32.61″ and 32.71″, a 0.10″ difference.
How much lift does 285/70R17 give over 305/65R17?
Almost none: the tire's radius changes by 0.06″. 285/70R17 is also 0.79″ narrower on paper, 0.39″ 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 305/65R17?
Yes. If it's set for 305/65R17, it will read about 0.8% slow: at an indicated 60 mph you'll be doing 60.5 mph. Worked out from the revolutions per mile the makers publish.
Can 285/70R17 go on the same wheel as 305/65R17?
Both fit a 17-inch wheel. Wheel widths approved for both run from 8.5″ to 10.0″.