Engine oil charted capacity verses actual dipstick level

[vetplus40]

I have a Merc 5.0 I/O that per the manual takes 5.5 quarts of oil. The manual does not reference levels "with or without" a filter change as do most auto manuals. After warming up engine and changing the oil and filter, the engine took only 4 quarts to reach the "fill" line. Even after running the engine and saturating the filter, I had to add very little oil. I also encountered this same anomaly with my last oil change.

In researching the issue, I found an old related post by "Don" that said the listed capacity was for a dry engine and that there would always be some residual oil left behind after an oil change. That makes sense to me with one notable caveat. Auto engines would also have residual oil left in the block after an oil change, but I have never seen this much difference between a listed capacity and an actual fill amount. I always use the "fill" line so I am comfortable running the engine. This is just basically a curiosity issue that I am trying to understand.

Thanks for reading.

 

[GA_Boater]

How do you remove the old oil? Drain plug or dip stick suck?

 

[vetplus40]

There is a flex drain line hose that can be pulled out through the drain plug. The diameter is small, but it does not appear to be plugged. Maybe the design of this engine allows for pockets of oil to remain inside, but the owners manual makes no mention of any oddities. The delta between recommended oil volume and actual volume is just odd to me.

 

[Scott06]

I’ve seen the same with my 5.0 regardless of wether I suck it from the dipstick or drain from hose. I put 4-4.5 qts in an it’s good on the dipstick. I’ve also seen later 5.0s listed as 4.5 qt capacity. https://www.michiganmotorz.com/mercruiser-engine-capacity-a-27.html

this lists 2000-2015 5.0 as 4.5 qts vs older ones at 5.5 qts... so I’m not sure what the capacity is on mine, I just go off the dipstick.

 

[tpenfield]

"took only 4 quarts to reach the "fill" line" Fill or Full . . . ? :noidea:

FWIW - since I draw the old oil out through the dipstick tube, I measure how much oil I take out, just to get a sense if I got it all.

 

[Rick Stephens]

Have the same issue with a V6. Manual says 4.5 quarts, less than 4 and it is over the mark. I put 4.5 qts in and keep it 3/8" high on the stick.

 

[Searay205]

Mercruiser 5.0 mpi exactly 4 quarts. I sucked out then pulled drain plug no oil came out. so when filling with new filter 4.25 quarts.

 

[vetplus40]

"took only 4 quarts to reach the "fill" line" Fill or Full . . . ? :noidea:

FWIW - since I draw the old oil out through the dipstick tube, I measure how much oil I take out, just to get a sense if I got it all.

Sorry for the typo, I meant "full". With respect to the oil change technique, I did the same routine with my Waverunner. I syphoned the oil out and measured it. Then replaced with it an equal amount. I was only able to get about 80% of the old oil out and hated mixing new oil with old. The only caveat between the boat motor and the Waverunner is that the Waverunner owners manual explained that there would be residual oil left and to measure the removed oil to know how much to replace. The Merc manual makes no such mention.

 

[vetplus40]

Mercruiser 5.0 mpi exactly 4 quarts. I sucked out then pulled drain plug no oil came out. so when filling with new filter 4.25 quarts.

Maybe there is a typo in my manual. Maybe the capacity should have read 4.5 instead of 5.5. 1 1/2 quarts is a bit of a delta.

 

[Kubaat3lover]

I’ve got different issue in my 4.3 merc, manual says 4 I’ve added 4qts and it still below add...