A dry sump offers many advantages, namely increased oil capacity and a lower center of gravity for the engine. Because the reservoir is external, the oil pan can be much smaller in a dry sump system, allowing the engine to be placed lower in the vehicle; in addition, the external reservoir can be as large as desired, whereas a larger oil pan raises the engine even further. Increased oil capacity by using a larger external reservoir leads to cooler oil. Furthermore, dry sump designs are not susceptible to the oil starvation problems wet sump systems suffer from if the oil sloshes in the oil pan, temporarily uncovering the oil pump pickup tube. Having the pumps external to the engine allows them to be maintained or replaced more easily, as well.
The oil capacity of a dry sump can be as big as you want. The tank holding the oil can be placed anywhere on the vehicle.
In a wet sump, turning, braking and acceleration can cause the oil to pool on one side of the engine. This sloshing can dip the crankshaft into the oil as it turns or uncover the pump's pick-up tube.
Excess oil around the crankshaft in a wet sump can get on the shaft and cut horsepower. Some people claim improvements of as much as 15 horsepower by switching to a dry sump.
(by allowing a lower hoodline).
The disadvantage of the dry sump is the increased weight, complexity and cost from the extra pump and the tank.