Oil Remaining in Engine During Oil Change - Interesting Chart Showing Oil Capacities

[rstcso]

I came across this chart on Mitchell1 DIY when looking at specifications for my 2025 Honda Pilot and thought it interesting that, according to them, an additional quart was required after engine overhaul. Is it realistic to believe a quart stays in the engine during a standard oil change? If so, is it staying in lifters, VVT systems, and all the other nooks and crannies? Have you seen this type of spec before?

 

[dnewton3]

Though the exact volume would be different for any application, the short answer is "yes". It's well known that residual oil is left in pretty much any engine during a normal OCI, and up to a quart is not uncommon.

 

[PontiacHO]

Turbo chargers, superchargers, and overhead cam-valvetrain especially hold oil. After years of traditional V8, V6, L6, and L4 engine tear downs for repairs and overhaul, I found not that much oil was left after draining the sump and removing the filter.

 

[4WD]

On my 5.3L’s … it’s a full quart when changing the oil filter - so when I leave a filter on - it’s that plus a few more ounces stranded. However, it’s an 8 quart fill - and typically between 5k-7k OCI’s … Probably an EP oil. …

 

[ctechbob]

Don't forget coolers. Hotter running GDI/Turbo cars with higher potential oil temps and now you've got manufs putting oil coolers on near everything whereas in days past it was usually only something you'd see on high performance cars.

 

[Ride_Red]

After overhaul, the engine is clean. All the little nooks and crannies are empty.
Just look at some open valve cover photos. There is a lot of oil just sitting around in the small spaces that you can see. There's a lot of spaces you can't see, too. It all adds up.

 

[RDY4WAR]

That's typical. Every engine will retain a certain amount of oil after an oil change, some much more than others. Some Powerstroke diesels will hold upwards of 4 quarts residual.

 

[duck__dodgers]

another reason to stick to shorter (however you define it) intervals. in this case, 14% of the oil will be old after a change.

I'm sure that there are peeps here who are OCD-fastidious about filter microns, moving up a viscosity, etc.....then keep the oil in the pan for 18,000 miles cuz "oil analysis"

IMO. YMMV. I'll grab the coffee while peeps flame it out, I got no dog in the fight

 

[RDY4WAR]

Those long intervals are accounting for the residual oil. It is a case though for taking 0 hour samples after the first 5-10 minutes of runtime following an oil change as opposed to a virgin sample from the bottle.

Sticking with the same oil will reduce additive clash risks from residual oil.

 

[The_Sheriff]

.
My Ford 2.5 duratec in my Maverick hybrid calls for 5.7 quarts with a filter change. I dump in a full 6 quarts and it fills it right to the optimum point on the dipstick. It’s tough to tell from this pic, but that’s where it is and it stays there the entire OCI which is typically between 10k-12k miles.
.

 

[rstcso]

After overhaul, the engine is clean. All the little nooks and crannies are empty.
Just look at some open valve cover photos. There is a lot of oil just sitting around in the small spaces that you can see. There's a lot of spaces you can't see, too. It all adds up.

I guess I never thought about the total amount could be so much. I understand when changing brands/families of oils, the first time using the new oil will have a combination of old and new. I've seen recommended intervals from a few hundred miles to thousands of miles.

I am switching from Amsoil SS to HPL PPPCMO and plan on running the first OCI 4k-5k miles after the switch. Sound reasonable?

 

[The_Sheriff]

I guess I never thought about the total amount could be so much. I understand when changing brands/families of oils, the first time using the new oil will have a combination of old and new. I've seen recommended intervals from a few hundred miles to thousands of miles.

I am switching from Amsoil SS to HPL PPPCMO and plan on running the first OCI 4k-5k miles after the switch. Sound reasonable?

.
Both oils are certainly of a high quality but I know that I’d run the HPL alot longer than 4-5k. What was your typical OCI with the Amsoil?
.

 

[thunderfog]

And if you want to get mathematically technical about it, under normal oil changes, the amount of residual oil from the original fill would asymptotically approach but never reach zero for the life of the vehicle in theory.