Potential Positive Effects:
* Improved Aesthetics: 20-inch rims generally give a car a more aggressive and sporty look. Larger wheels can fill out the wheel wells better, enhancing the car's overall visual appeal.
Potential Negative Effects:
* Rougher Ride: Larger rims typically require lower-profile tires (tires with shorter sidewalls). Lower-profile tires offer less sidewall cushioning, leading to a harsher ride. You'll feel more bumps and imperfections in the road.
* Increased Road Noise: The reduced sidewall height of lower-profile tires means less sound absorption, resulting in increased road noise inside the cabin.
* Reduced Comfort: The combination of a harsher ride and increased road noise significantly diminishes overall driving comfort, especially on rough roads.
* More Susceptible to Damage: Lower-profile tires are more prone to damage from potholes, curbs, and other road hazards. Repairing or replacing damaged tires and rims will be more expensive.
* Potentially Increased Un-sprung Weight: Larger rims, especially those made of heavier materials, can increase the unsprung weight of the vehicle. This can negatively affect handling and braking performance, making the car feel less responsive. (However, this is less of an issue with modern lightweight alloy rims).
* Speedometer Inaccuracy: If the diameter of the new wheel/tire combination is significantly different from the original, your speedometer and odometer readings might become inaccurate. This can be corrected with recalibration, though.
* Reduced Fuel Efficiency: Larger, heavier wheels and lower-profile tires can slightly reduce fuel efficiency due to increased rolling resistance.
In short: While 20-inch rims can enhance a car's appearance, they often come at the cost of ride comfort, handling, and potentially fuel economy. Whether the trade-off is worthwhile depends entirely on individual preferences and priorities. Consider your driving style and road conditions before making the switch. It's also crucial to carefully choose tires that balance performance and comfort.
