195/70R18 vs 215/65R18
Going from one to the other changes the overall height by +0.9 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 195/70R18 | 215/65R18 | Change |
|---|---|---|---|
| Overall height | 28.7" | 29.0" | +0.9 % |
| Sidewall | 5.37" | 5.50" | +2.4 % |
| Section width | 195 mm | 215 mm | +10.3 % |
| Circumference | 90.3" | 91.1" | +0.9 % |
| Revs per mile | 702 | 695 | -0.9 % |
| Axle height | 14.37" | 14.50" | +3.3 mm |
| Approved rim width | 5.5–7" | 6–8" | 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 195/70R18. Fit 215/65R18 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.3 mph | +0.3 |
| 50 mph | 50.4 mph | +0.4 |
| 70 mph | 70.6 mph | +0.6 |
| 90 mph | 90.8 mph | +0.8 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,089 on the road, so it under-counts by 89. At a true 70 mph the first turns 818 times a minute, the second 811.
What drivers reported
195/70R18 carries 1 complaints. Nobody has filed one naming 215/65R18.