Car diffuser oil is the same blend as reed diffuser oil: 15–20% fragrance oil in Reed/Electric Diffuser Base. At 20%, a 10 ml hanging bottle holds 8 ml base and 2 ml fragrance oil.
Most hanging car diffuser bottles hold 8–10 ml, about a third of an ounce, so one 16 oz batch fills about 47 bottles. Check the oil's IFRA limit before setting the load. Fragrance oil comes in 1 oz, 4 oz, and 16 oz; Oil to buy is the smallest bottle that covers the batch. Other sizes: fragrance load calculator.
| Finished batch | Base | Fragrance oil | Oil to buy |
|---|---|---|---|
| One 10 ml bottle | 8 ml | 2 ml | 1 oz |
| 4 oz (about 11 bottles) | 3.2 oz | 0.8 oz | 1 oz |
| 16 oz (about 47 bottles) | 12.8 oz | 3.2 oz | 4 oz |
| 1 gallon (about 378 bottles) | 102.4 oz | 25.6 oz | two 16 oz bottles |
Make hanging car diffusers with the same base and load as a reed diffuser, in small bottles with a wooden cap that wicks the scent.
what you'll need
- Reed/Electric Diffuser Base
- Fragrance oil of your choice
- Hanging car diffuser bottles with wooden caps (8–10 ml)
- Small funnel or pipette
- Mixing container with a pour spout
- Labels and hang cords
step-by-step instructions
- Step 1. Measure 12.8 oz of Reed/Electric Diffuser Base into a mixing container.
- Step 2. Add 15–20% fragrance oil within the oil's IFRA limit (3.2 oz for a 20% load in 16 oz).
- Step 3. Stir until uniform, with no layering or cloudiness.
- Step 4. Fill one bottle to the shoulder, cap it, tip it upside down for a few seconds to wet the wooden cap, and hang it for a day to check scent and that the cap wicks evenly.
- Step 5. Fill the rest of the bottles with a funnel or pipette, leaving room below the neck so the cap seats without overflow.
- Step 6. Screw on the wooden caps, wipe any drips, add the cord and label, and pack upright. Tell customers to tip the bottle to re-wet the cap when the scent fades.
example batch
For Makers: Blend Reed/Electric Diffuser Base with 15–20% fragrance oil within the IFRA limit for the oil. Stir until uniform and test one bottle before filling the run. Example Batch: 12.8 oz base + 3.2 oz fragrance oil = 16 oz finished product (20% load), about 47 ten-millilitre bottles. For End Users: Tip the bottle upside down for a few seconds to wet the cap, then hang. Keep the bottle upright afterward and tip again when the scent fades.
pro tips for makers
- Undiluted fragrance oil can mark plastic and painted surfaces. Keep caps dry before hanging and tell customers to wipe any drips.
- Woody, amber, and clean scents hold up best in a hot car. Test a bottle on a dashboard in the sun before committing to a scent.
- Car diffusers sell well in pairs and as add-ons to room spray and reed diffuser orders.
- Print the re-wet instruction on the hang tag; it is the question customers ask most.
why this base works
- Made for passive diffusion through reeds and wooden caps
- Holds 15–20% fragrance oil depending on IFRA limits
- Excellent fragrance solubility, so the blend stays clear in a clear bottle
- Balanced evaporation: scent on the first day and for weeks after
common questions
Is car diffuser oil different from reed diffuser oil?
No. It is the same Reed/Electric Diffuser Base at the same 15–20% load, in a smaller bottle with a wooden cap in place of reeds.
Can I use the room spray base instead?
No. The room spray base is alcohol, which flashes off in a hot car. The diffuser base is made to release scent slowly through a wick.
How much fragrance oil per bottle?
At 20%, a 10 ml bottle takes 2 ml of fragrance oil and 8 ml of base. A 16 oz batch fills about 47 bottles.
Ready to start making? Grab your base and a fragrance oil to match.
