215/60R18 vs 195/70R18
Going from one to the other changes the overall height by +2.1 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 215/60R18 | 195/70R18 | Change |
|---|---|---|---|
| Overall height | 28.2" | 28.7" | +2.1 % |
| Sidewall | 5.08" | 5.37" | +5.8 % |
| Section width | 215 mm | 195 mm | -9.3 % |
| Circumference | 88.5" | 90.3" | +2.1 % |
| Revs per mile | 716 | 702 | -2.1 % |
| Axle height | 14.08" | 14.37" | +7.5 mm |
| Approved rim width | 6–8" | 5.5–7" | overlap 6–7" |
Both are approved on a rim 6" to 7" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 215/60R18. Fit 195/70R18 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.6 mph | +0.6 |
| 50 mph | 51.0 mph | +1.0 |
| 70 mph | 71.5 mph | +1.5 |
| 90 mph | 91.9 mph | +1.9 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,210 on the road, so it under-counts by 210. At a true 70 mph the first turns 836 times a minute, the second 818.
What drivers reported
Nobody has filed a complaint naming 215/60R18. 195/70R18 carries 1.