DSW is a blend of light sweet crude oil produced in the interior of the US and used to fulfill the NYMEX crude contract

DSW is a blend that can contain a wide variety of inland North American crudes, including Canadian sweet, Bakken, Niobrara, and WTI.

The primary blending and trading point for DSW is the Cushing crude oil hub in Oklahoma in the US

The DSW blend is the basis for the NYMEX light sweet crude contract, which is an important overall market index for global crude market.  Physical deliveries of DSW for the contract are at Cushing.

The specification for DSW is:

• API - 37-40

• Sulfur - less than 0.44

DSW is sometimes referred to as WTI Cushing, but this is a bit misleading.  While true WTI (from West Texas) can be blended into DSW, the spec for DSW is worse than for WTI so DSW is not a true substitute for WTI