the discussion about oil in Lainey's P-car thread got me thinking.

Mercedes doesn't recommend draining the oil via the drain plug.
They siphon it off with a pump via the dipstick. The filter is at the top of the motor.

So does anyone siphon or used the good old drain plug?

 

I use drain plug on all cars I've own. Car should be at operating temp. Which makes for a tricky drain plug removal process, to avoid "ouchies." Or dropping the gasket/plug into the drain pan.

I also change oil filter each time and prefill the darn filter can to about 1/4 height, with new oil.

 

Boat motors get siphoned. Car engines get drained. Why does the location of the filter matter?

 

I've never heard of or thought of siphoning oil. But, its not necessary with my 8hp Honda boat motor. The location of the filter just determines how much oil runs down your arm when removing. I fill a new filter up about 1/2 way when installing.... unless its an up-side-down filter.

 

Mine does'nt even have a dipstick...

 

When filter is on the top side, it is readily accessible without putting the car up on jacks, ramps, or lift.
whole process is quicker and safer.

 

Drain. I installed a Fomoto drain valve on the S. Short of the oil catch pan, I can do everything from the top. For the truck, I take it to the local mechanic down the street because Ford was so kind as to put a crossmember directly below the drain plug so oil goes everywhere except in the catch pan.

 

I see. I can reach the filter on the S without jacking up the car as well, but I get your point.

For me, it comes down to what I would have to pay for one that actually works well and does not leak. I've used cheapo siphons and they are slow and a mess. I've seen video of the mighty vac ($80) leaking out of the handle. So how much is a really good electric unit or compressed air powered unit?

Next is the issue of how much oil siphoning leaves behind in your oil pan. I understand that all cars are different in this regard. In one car you may be able to get more by siphoning than draining, but that is not universal.

 

I've got a LiquiVac that I used on my old zero turn lawn mower. It had an issue with the drain that would have required removing the engine to fix. Haven't used it in years, but it came in handy this fall. The diff on the kit car does not have a drain plug, so I used it to siphon out the old fluid. It has a valve, that when closed, allows you to pump up a vacuum. I like this model as replacement parts are available.




Models | LiquiVac

 

No longer owning any vintage classics or hobby cars I go with what the dealership chooses. Don’t change my oil anymore since the local auto parts retailer(s) always claims that their recycle tanks are full and can’t accept my used oil. Multiple phone calls and inconvenience was necessary just for the disposal of my used oil. If I still changed my oil it would probably be heated and then drained.

Gary