Engine Oil Capacity vs Engine Size

[cps13]

Hi all,

A colleague and myself have been debating whether "generally speaking/rule of thumb" a larger engine automatically means it has a greater oil capacity.

I reckon that it isn't a given that the larger the engine the more oil needed and that there are many engines out there which require more oil than larger ones.

i.e. the engine in a 1.4 VW polo needs more oil than a 1.6 Mk 5 golf.

Anybody have a definitive answer.

[944fan]

I guess it depends on the design of the engine. I have a 2.4 V6 and that takes 5.5 litres, which is great when they only sell it in 4 lt bottles at £40 a pop so it costs £80 per oil change. The rest is used topping up becasue it leaks oil eveyrwhere!!

[anonymous-user]

There are pretty much 2 main driving factors behind engine oil capacity:

1) Service intervals and oil degredation: Getting longer service intervals requires more oil capacity, so newer cars that go 20k miles between services tend to have a larger capacity
2) Amount of oil "hang up" in the engine oil return paths: Depending upon the design and orientation of the powertrain, so engines can hold large volumes of oil "hung up" in the head or crankcase.

Oil capacity does scale with engine size, but usually only takes significant jumps with number of cylinders, as these extra physical dimensions are what traps the oil

[TallPaul]

I would say design age has more of a factor on oil capacity than engine size. The same "family" of engines will have the same oil capacity regardless of their cc's. Designers are always trying to get more power/ economy out of their power-trains, so reducing pumping losses and churning efforts by having less oil in a sump is a good way to free up some extra HP, and as modern oils get better at maintaining their viscocity for longer, in more extreme environments, less is needed.