Should You Really Be Pre-Filling Your Oil Filter?
I've performed countless oil changes in my personal vehicles over the last 45 years. I had the process drilled into my head at an early age by changing the oil in my family's dirt-track race car several times throughout the racing season. My dad, well technically my step-dad, was a stickler for procedure, being a long-time F-16 jet engine mechanic for the Oklahoma Air National Guard. In his opinion, as well as experts like The Oil Geek, pre-filling the engine oil filter during an oil change is a step that should never be skipped.
The number one reason for filling the oil filter with fresh oil before installing it on the engine is to reduce the amount of time it takes to pressurize the oil system. If the oil filter is empty and dry, the oil pump has to deliver enough oil to saturate the material inside the oil filter and fill it with oil before it can pressurize the rest of the system, a task that can take several seconds according to The Oil Geek's tests.
What if my car's oil filter isn't installed vertically?
If your car's oil filter screws on vertically it's easy to install it filled with oil. However, if it's the type that screws on in a horizontal orientation, like the one on my 2018 Ram 3500 6.4L HEMI, it's not possible to keep it filled with oil while installing it.
Getty's Garage posted a YouTube video where they performed an oil change on a Ram 2500 with the same engine. In that video they stated that pre-filling the oil filter wasn't necessary due to the small size of the filter. Their argument against pre-filling was that it only took a short time for the system to fill the filter and pressurize the system avoiding any engine damage.
When I change the oil in my truck, since it's not possible to install the filter full of fresh oil, I fill the new filter with oil before I do anything else. While I'm draining the old oil and removing the old filter, the new filter sits on the workbench soaking up the new oil and saturating the filter material inside.
When I'm ready to install the newly soaked filter, I pour the excess oil from the filter back into the oil container and use the residual oil to lubricate the filter's rubber seal before installation. Forgetting to lubricate the oil filter seal is one of the common mistakes people make when changing oil in their vehicle. and can lead to oil leaks.