The 2.22 and the 1.78 are in the manual as imperial gallons for both. The 1.78 says, "change quantity." I have no idea where the 0.44 imperial gallons difference is.

 

Get an LNE magnetic drain plug. That may ease your concerns. Also try draining your oil at different angles. One time with the rear up, and one time with the front up. See if there is any difference in the amount of oil drained.

 

Correction on earlier post, LNE sells a deep sump kit which adds a spacer between the engine case and sump plate. They do not sell a new sump plate. Their spacer adds capacity to the oil system.

Also it hasn't been mentioned yet, but drain your oil when the engine is warm, you'll get more bang for your buck on drain time and oil drained vs. a cold engine.

 

The factory manual calls for the engine to be up to a certain temp (70C or maybe its 80C I forget) and a drain time of 20 minutes. The car is expected to be level since the lifts in the dealer service bays are level.

I've drained the oil in my Porches more than once and while I have the engine hot the cars are on ramps. I drain the oil for as long as the oil runs more than a thin stream. I do not have the patience to wait until the stuff stops running out entirely.

There's no need to remove the pan. It is a waste of time. Besides if the pan is oil tight now it may not be oil tight afterwards. IOWs, if it ain't broke don't fix it.

There's no need to flush the engine. There will not be enough flow velocity to remove any particles at the bottom of the oil pan. Besides if they're light enough to be flushed out the drain hole they will have been inhaled/ingested by the oil pump and pulverized by the oil pump and the fragments in the oil filter housing or in the oil filter element.

Early on I checked to see if there was any benefit to having my car level and I found there wasn't any, at least within reasonable amounts of tilt. like the rear of the car raised from backing the car up on a pair of Rhino Ramps.

The engine is designed to encourage any oil that can drain back into the sump to drain into the sump when the engine is off and the car is sitting at almost any angle.

If the oil didn't do this it would collect and the engine would starve for oil even climbing or descending a grade.

In short, get the engine up to temp.

Back the car up on ramps or use a lift to lift the car up so you can get under/work on the car safely.

Remove the drain plug -- careful the oil is hot! -- and let the oil drain 20 minutes. Remove and replace the filter. Use a new filter housing o-ring.

Reinstall the drain plug using a new seal washer. Be sure you use a good torque wrench to properly secure the drain plug and oil filter housing.

Dump into the engine the appropriate amount of oil. This varies from model to model and can vary from car to car as Porsche might have made an internal engine change during a model run that resulted in a slight change in the engine's oil capacity.

The techs get updates/bulletins to the factory manuals that let them know what the right amount of oil is.

You can ask and probably a tech will tell you. Or the parts department might tell you if you supply a VIN.

Add this amount of oil to the engine. Double check you added the right amount of oil. Count the empty bottles twice.

Before you start the engine double check under the car you didn't leave a drain plug out of the hole.

After starting the engine and driving the car off the ramps turn off the engine and let it sit while you put things away.

After a while check the oil level. It should be ok. If not the oil level sensor/sender is defective. It is by putting in the correct amount of oil that allows one, gives one the chance to verify the oil level sensor/sender is working properly.

Sincerely,

Macster.

 

In addition to the above excellent advice on the initial fill after drain I would recommending adding slightly less than what is called for (perhaps .5 to .25 fewer quarts), running the engine for about 30 seconds or so, shutting it off, waiting another interval of time (perhaps 10-15 minutes) and then adding the remaining amount to get to the acceptable level.