255/70R15 vs 30x9.50R15
30x9.50R15 is 3.3% taller (+0.94 in) and 0.54 in narrower than 255/70R15.
30x9.50R15 is 3.3% taller than 255/70R15. It often still fits, but expect a noticeable speedometer error and check clearance at full steering lock.
| 255/70R15 | 30x9.50R15 | Change | |
|---|---|---|---|
| Diameter | 29.06″ | 30.00″ | +0.94″+3.3% |
| Width | 10.04″ | 9.50″ | −0.54″−5.4% |
| Sidewall | 7.03″ | 7.50″ | +0.47″+6.7% |
| Circumference | 91.3″ | 94.2″ | +3.0″+3.3% |
| Wheel | 15″ | 15″ | Same |
| Revs per mile | 694 | 672 | −22 |
Real speed on 30x9.50R15.
Change in height under the axle.
On the same wheel, split inboard and outboard.
Shop 30x9.50R15 tires
Opens the store’s own searchPrices and stock change often, so check a few stores. We don’t earn anything from these links.
255/70R15 or 30x9.50R15?
Can I use 30x9.50R15 instead of 255/70R15?
30x9.50R15 is 3.3% taller than 255/70R15. It often still fits, but expect a noticeable speedometer error and check clearance at full steering lock. Also match or beat the original load index and speed rating, and check that the wheel width suits the new tire.
Will my speedometer be off?
At an indicated 60 mph on 30x9.50R15 you are really doing 62.0 mph if the speedometer was set up for 255/70R15. Going the other way, 255/70R15 would make it read 58.1 mph at a real 60.
How much ground clearance does it change?
Half the diameter difference: +0.47 in (+12 mm) under the axle.