Question 1

How much tire size change is acceptable?

Accepted Answer

Most manufacturers and regulations allow ±3% overall diameter change. Beyond this, speedometer error becomes significant, and ADAS systems (ABS, ESC) may malfunction. Always check with your vehicle manufacturer for approved alternative sizes.

Question 2

Does wider tire always mean better grip?

Accepted Answer

Wider tires increase contact patch area, improving dry traction and cornering grip. However, they increase rolling resistance (reducing fuel economy by 1-2% per 10mm width), are more prone to aquaplaning, and add unsprung weight. Narrower tires can actually perform better in snow and wet conditions.