The funnel uses the standard Toyota M37x3.0 oil cap thread so it'll screw right into the oil fill hole, which makes the funnel really stable, and the "seat" on the funnel neck creates a seal so the oil can't escape up the threads.
When printing, be sure you print the funnel upside down (threads at the top) and it shouldn't need supports. At least, my print didn't. I also found you should use a small brim to give it more "stick" to the build plate.
Important Note: When using ANY printed funnel that incorporates threads, don't use force to tighten as you would with the oil cap. This can result in breaking the threads. These funnels are designed, and will properly function, with just "spin on" tightness.
Due to the chemical makeup of filaments, you should also ensure you are printing with a filament that is resistant to oil, such as PLA. You should also limit your funnel to this use, as other chemicals (such as Gasoline) may not be compatible.
JodianG_ToyotaOilFunnel.stl | 1.0MB |