Can I use a different tire size?
Often yes — if the total diameter stays within about ±3% of the original. Example: swapping 205/55R16 for 215/55R16 changes the diameter by just +1.7%. Here's how to check any swap.
A worked example
| Tire | Sidewall | Total diameter | Difference |
|---|---|---|---|
| 205/55R16 (original) | 112.8 mm | 631.9 mm | — |
| 215/55R16 | 118.2 mm | 642.9 mm | +1.7% ✓ |
| 225/45R16 | 101.3 mm | 609.0 mm | −3.6% ✗ |
What changes when the diameter changes
A bigger diameter makes your speedometer read low (with +1.7%, a true 100 km/h shows about 98) and slightly raises gearing; a smaller one does the opposite. Beyond ±3%, the errors and the strain on ABS/traction systems get too large — that's the industry guideline.
Frequently asked questions
Can I put 215 tires instead of 205?
Usually yes if the aspect ratio and rim match: 215/55R16 vs 205/55R16 is only +1.7% diameter, within the ±3% guideline. Check clearance and load rating too.
What happens if I use a bigger tire size?
Your speedometer reads slightly low, gearing rises a touch, and beyond ~3% larger you risk rubbing and confused ABS/traction systems.
How different can tire sizes be?
The common guideline is to keep the total diameter within ±3% of the original, and never go below the original load and speed ratings.