Why doesn't the F150 utilize a resistor cap on the spark plug wire?

The correct answer is based on the functionality of the spark plug wire in the F150's ignition system. The F150 uses a resistor wire as the primary component of the spark plug wire, which is designed to limit electromagnetic interference while still allowing for efficient spark delivery.

Resistor wires inherently have resistance built into their structure, which serves the purpose of reducing radio frequency interference that can occur in ignition systems. This design eliminates the need for an additional resistor cap because the wire itself provides sufficient resistance to help manage any potential interference issues, ensuring proper engine performance without compromising the ignition system's efficiency.

In contrast, options suggesting that a resistor cap is required or indicating that the model was designed without it do not accurately reflect the design principles of the ignition system. Moreover, the notion that a resistor cap may cause interference with performance is not applicable, as the system is optimized without the additional resistance that a cap would introduce.