What is a Dry Sump Engine?

Mercedes-Benz Dry Sump Engine

Wet Sump

The combustion engine ubiquitous with the automobile is a wet sump engine. It is called a wet sump engine because even when at rest, the oil remains in the crankcase, collecting in the oil pan at the bottom. Although this is the most practical application for a car, the excess oil in the sump can cause uncontrollable movement of air, or wind, that works against the pistons. This, and the imbalance associated with needing a spot for all the oil inside the engine are two of the big performance drawbacks that led to the invention of the dry sump engine some 70 years ago.

Meet the transforming 2017 Mercedes-AMG GT R

Dry Sump

Instead of keeping all the oil in the crankcase, dry sump engines pump oil in and out as needed to and from an external oil reservoir. Dry sump engines still have oil pans at the bottom of the crankcase, but is sucked completely dry of oil as new oil is simultaneously scavenged throughout the engine. Special pumps are required to do this that create a tight vacuum seal in the engine, conducing more power. Dry sump engines help the engine stay cleaner, but because they are only used in racing applications, they don’t last as long.

Mercedes-AMG GT S vs Mercedes-AMG C63 S

Mercedes-AMG C63

The Mercedes-AMG C63 uses the same 4.0L Inside V Biturbo V8 that the GT does with one exception, it is a wet sump engine. What is the difference?

The C63 actually has 37 more lb-ft of torque than the GT S, both having the same amount of high-end horsepower. Both redline at 7,000 RPM and the C-Class gets a few more miles per gallon than the GT S. As it turns out, what you get with the GT S that you don’t with the C63 is the difference between a race car that is street legal, and a street car that can keep up on a track. If you have any questions about the Mercedes-Benz Dry Sump Engine, leave a comment below or stop in at Mercedes-Benz of Arrowhead to see one for yourself!