Wet Sump Oil System (and Dry...)

In engine oiling systems, there are two main types - wet sump and dry sump.  Most every production engine in the world uses a wet-sump system because they are low-cost and light-weight.  Not to mention, they are very simple.  There is an oil pan at the bottom of the engine where the oil is collected.  The oil pump circulates oil out of the pan, through the engine, and back into the oil pan again.  This system is much cheaper than a dry sump system, mainly because it has less parts.  The oil pan in the wet-sump system is where the oil is stored and recirculated, whereas in the dry-sump system there is an external tank for storing oil and an additional external pump.  

Pretty much all of the cars and trucks we see on the road have a wet-sump oil system.  The main place to see a dry-sump system would be at a racetrack.  The way the system functions for pumping oil through the system is much more efficient (in certain ways).  They have better "slosh control" (a.k.a. better containment/control of the oil within the pan) and a larger oil capacity, plus the engine can be mounted lower to the chassis because of the smaller pan near the bottom.  Of course with efficiency comes cost, which is mainly why they are only on racecars.  Their main concern is power, and the wet-sump system tends to rob horsepower.  One exception is dragsters, which use the wet-sump system, because they have room for a large oil pan and extra performance-enhancing pumps.  The system is much easier to work with in-between runs, and cooling of the system isn't critical since the engine only runs a couple minutes at a time. 

It's funny that this system is in every car we see on the road, yet I had no idea that's what it was.  I figured "wet-sump" was some sort of special aviation term... guess not! 

-TB