Western Canadian Select (WCS) Price

What WCS is

WCS is a blend of heavy conventional crude and bitumen from Alberta's oil sands, diluted with condensate or synthetic crude so it can flow through pipelines. It was created in December 2004 by EnCana (now Cenovus), Canadian Natural Resources, Petro-Canada (now Suncor) and Talisman (now Repsol). Blending takes place at Hardisty, a storage and pipeline hub in eastern Alberta.

At about 21° API and 3–3.7% sulfur, WCS is a heavy sour crude. It needs complex refineries with cokers and hydrotreaters to process. Most of those refineries are in the US Midwest and on the US Gulf Coast. See API gravity and sweet vs sour crude for the quality terms.

Why WCS trades below WTI

The WCS-WTI differential has three parts:

1. Quality. Heavy sour crude yields more residual fuel and less gasoline and diesel, and refiners must pay to remove sulfur. Even at the same location, WCS would sell below light sweet WTI.
2. Transport. Hardisty is far inland and far from most of its buyers. Pipeline tariffs or rail costs to the US Midwest, Gulf Coast or Pacific coast come off the price paid at Hardisty.
3. Pipeline capacity. When Canadian output grows faster than export pipelines, barrels back up in Alberta. Producers must use more expensive rail or discount crude to clear the market, and the differential blows out.

The third factor caused the most extreme moves. In autumn 2018 the differential widened to a record of around $50/bbl and WCS fell below $14/bbl in November 2018. Alberta's government responded with mandatory production limits from 1 January 2019.

The Trans Mountain Expansion (TMX) runs from Edmonton to the Westridge Marine Terminal near Vancouver. It raised the system's capacity to about 890,000 barrels per day, nearly triple the old line. According to the CER, Westridge can export up to 630,000 b/d, an average of 23 tankers a month left the terminal between June 2024 and July 2025, and the Trans Mountain system has had no apportionment since start-up. For the first time, large volumes of Canadian heavy crude can reach Asia and the US West Coast by sea instead of relying almost entirely on pipelines to the US.

What moves the WCS differential now

• Canadian production vs pipeline space. Rising oil sands output will eventually fill TMX and the Enbridge Mainline again.
• Competing heavy crude on the US Gulf Coast. Supply from Mexico, Venezuela and the Middle East competes with WCS for coking refineries. The IEA noted that the US Strategic Petroleum Reserve release and higher Venezuelan exports weakened WCS in March 2026. See the Strategic Petroleum Reserve guide.
• Freight. Higher tanker rates reduce the netback for barrels shipped from Vancouver. The IEA reported that High-TAN crude FOB Vancouver fell to $18.95/bbl below ICE Brent in March 2026 as freight costs rose.
• Seasonal diluent demand. More condensate is needed in winter to keep bitumen flowing, which raises blending costs.
• Refinery outages. Maintenance at large Midwest refineries cuts demand for heavy Canadian crude.

How WCS is traded

WCS is quoted as a differential to the NYMEX WTI calendar-month average. Producers, refiners and traders hedge with WCS differential futures and swaps on CME, which can be cleared through CME ClearPort or NGX. WCS is also assessed on the US Gulf Coast (WCS Houston), where it competes directly with other heavy sour crudes. The Canada oil production page covers output and export volumes, and the crude oil benchmarks guide compares WCS with other grades.