Crude Oil Grades & Specifications

"Light," "medium," and "heavy" describe crude oil density. Density is commonly expressed as API gravity: higher API gravity means lighter crude. Lighter crudes typically require less complex processing to produce high-value fuels, while heavier crudes often require more upgrading capacity at the refinery. There isn't one universal cutoff used everywhere; some references use higher thresholds for "light" (commonly above 38° API), while some market classification charts use lower thresholds (for example, "light" starting around 31.1° API). These cutoffs are best treated as classification conventions rather than absolute scientific boundaries.

"Sweet" and "sour" refer to sulfur content. Lower-sulfur crude is called "sweet," and higher-sulfur crude is called "sour." Sulfur matters because it affects refinery processing requirements and the cost to meet fuel sulfur regulations. Like API-based categories, sulfur cutoffs vary by reference. A common definition is "sweet" below 1% sulfur and "sour" above 1%; some market classification charts use a tighter split (for example, sweet below 0.5% sulfur, sour at or above 0.5%).

Benchmarks are reference prices used widely to price other crude grades as premiums or discounts ("differentials"). WTI is the key North American benchmark linked to NYMEX (CME) Light Sweet Crude Oil futures with physical delivery at Cushing, Oklahoma. Brent is a major international benchmark associated with North Sea crude pricing and the broader Dated Brent/BFOE ecosystem. Dubai/Oman benchmarks are core pricing references for medium sour crude delivered from the Middle East Gulf into refinery markets, especially in Asia. OilMonster uses these benchmark references to help users compare regional price levels and understand how different grades relate to global pricing hubs.

Yes. Use the "Compare crude grades" tool to select two grades. You'll see a side-by-side view of key specifications (such as API gravity and sulfur content) and can open the full comparison with a price history chart. Comparisons are most meaningful when you compare grades that are priced in similar market contexts (for example, both tied to the same benchmark region), but the tool is also useful for understanding how quality differences line up against price differences.