* Tire size: The rim size is only part of the equation. The overall diameter of the tire (rim plus sidewall) significantly impacts performance. A 20-inch rim with a low-profile tire (short sidewall) will have a similar overall diameter to a smaller rim with a taller tire. Low-profile tires increase rotational inertia, requiring more effort from the engine to accelerate.
* Engine size and power: A 4-cylinder engine's power output is crucial. A high-performance 4-cylinder (like some turbocharged engines) might handle 20-inch rims better than a low-powered, naturally aspirated 4-cylinder.
* Vehicle weight: A heavier vehicle will struggle more with larger, heavier rims and tires, regardless of engine type.
* Driving style: Aggressive driving will exacerbate the negative impacts of larger rims more than a gentle driving style.
In general:
Larger rims and low-profile tires tend to:
* Reduce acceleration: Increased rotational inertia requires more engine power to accelerate.
* Decrease fuel economy: The extra weight and increased rolling resistance reduce fuel efficiency.
* Harsher ride: Low-profile tires offer less sidewall to absorb bumps, resulting in a less comfortable ride.
* Increased wear and tear: They are more susceptible to damage from potholes and other road imperfections.
Conclusion:
While 20-inch rims *might* be manageable on a 4-cylinder car, it's likely to negatively impact performance, fuel economy, and ride comfort, especially if the engine is underpowered or the tires have low profiles. It's not inherently impossible, but carefully consider the trade-offs before making the switch. Look at reviews and forums related to your specific car model and engine to see if others have made this upgrade and what their experiences have been.
