The number of drops of essential oil required for a car diffuser can vary depending on the specific diffuser model and your personal preference for scent strength. However, as a general guideline, you can start with 2-4 drops of essential oil for a small car diffuser.
Keep in mind that car diffusers are typically smaller than regular household diffusers, and they require less essential oil to avoid overpowering the confined space of a vehicle. It's always a good idea to start with fewer drops and adjust based on your preference.
If you find that the scent is too strong, you can reduce the number of drops in subsequent uses. On the other hand, if you prefer a stronger aroma, you can add a couple more drops of essential oil. Experimentation will help you find the right balance and intensity of fragrance for your car diffuser.