Intelligence · Crude grades · Updated March 2026

Oil is not one thing

When Hormuz closes, the question is not just how much oil is disrupted — it is which oil. Arab Light and Urals are both crude. They are not interchangeable. The refinery built for one cannot simply run the other. This is the grade map.
Sources: EIA crude assay database · Saudi Aramco product specifications · ADNOC Murban specifications · S&P Global Platts crude oil assays · IEA Oil Market Report · BP Statistical Review 2025 · Argus Media · March 2026
The two numbers that define every crude
API°
Gravity — how light or heavy
API gravity measures crude density. Higher number = lighter crude. Light crudes (35°+) yield more gasoline and diesel per barrel with less processing. Heavy crudes (<25°) yield more residual fuel oil and require more complex, expensive refineries to crack into valuable products.
Heavy <25° Medium 25–35° Light 35–45° Condensate 45°+
S%
Sulphur — sweet or sour
Sulphur content determines processing cost. Sweet crudes (<0.5% S) require less treatment, produce less pollution, and command a premium. Sour crudes (>0.5% S) require desulphurisation units — expensive capital investment. A refinery configured for sweet crude cannot simply process sour crude without major modifications.
Sweet <0.5% Medium 0.5–1% Sour 1–2% Very sour 2%+
Why grade matters — refinery configuration
Three refinery types — built for different crudes, not interchangeable
Hydroskimming
Simplest · lowest cost · limited flexibility
Distills crude into fractions, removes sulphur. Can process light sweet crudes efficiently. Produces significant residual fuel oil — a low-value product. Cannot handle heavy or high-sulphur crudes profitably.
Brent Johan Sverdrup Bonny Light
Cracking
Medium complexity · most common globally
Adds a catalytic cracker to convert heavier fractions into gasoline and diesel. Can handle medium sour crudes. The standard configuration for most Asian refineries built in the 1980s–2000s.
Arab Light Murban Basra Light Urals
Coking / hydrocracking
Most complex · highest capital cost · maximum flexibility
Adds a coker or hydrocracker. Can process heavy sour crudes profitably. These refineries were built specifically to run cheap Gulf heavy grades — they lose their economic advantage when forced to run lighter, more expensive crudes.
Arab Heavy Iranian Heavy Kuwait Export Venezuela
The grade mismatch problem — why Hormuz disruption is not fungible
Japan's Nagoya refinery, configured for Arab Medium sour crude, cannot simply switch to Norwegian Johan Sverdrup light sweet crude. The catalytic equipment is calibrated for sulphur removal. Running light sweet crude through a complex coking unit generates the same products at significantly higher cost — and the lighter crude may cause operational instability. This is why Hormuz disruption is not simply solved by "buying oil elsewhere." The oil elsewhere is a different product for a different machine.
API gravity vs sulphur content — all major grades
The crude quality map
Higher API = lighter, more valuable. Lower sulphur = sweeter, easier to process. The bottom-right quadrant (light sweet) commands the highest premiums.
Gulf / Middle East
Russia / FSU
North Sea / Europe
Africa
Americas
Gulf producers — Hormuz-dependent
Arab Light
Saudi Arabia
The regional benchmark. Sets the pricing tone for 9M bbl/d of Asian crude.
API gravity
34.2°
Medium light
Sulphur
1.77%
Medium sour
Production
~6M
bbl/d · curtailed
HeavyLight

The flagship grade — the one Aramco's OSP is built around. Sets the price signal for Kuwait, Iraq, Iran and Qatar, all of which price relative to Arab Light. The single most important crude in the global pricing system.

Requires a cracking or hydrocracking refinery. Japan's JXTG, India's Reliance, China's Sinopec are all configured to run it. Cannot easily be replaced by North Sea light sweet grades without significant yield loss.

Main buyers China Japan India South Korea US Gulf Coast
Hormuz route partially disrupted. Rerouting via Yanbu at record pace — port at capacity. OSP for April loading raised to +$2.50 vs Oman/Dubai.
Arab Heavy
Saudi Arabia
The discount grade. Only profitable for refineries built specifically for it.
API gravity
27.4°
Heavy
Sulphur
2.85%
Very sour
OSP diff
−$4.2
vs Arab Light
HeavyLight

Requires the most complex coking refineries. The discount to Arab Light ($4.20/bbl in March 2026) is near its widest in 18 months — signalling that complex refinery capacity is constrained and buyers prefer lighter grades during the crisis.

The widening Light-Heavy spread is a crisis signal: it shows that heavy sour crude is becoming harder to place because the complex refineries configured to process it are operating at reduced rates or facing feedstock disruption.

Main buyers China (coking refineries) India US Gulf Coast
Discount widening. Complex refinery utilisation falling. Light-Heavy spread now $4.20/bbl — near 18-month wide.
Murban
UAE (ADNOC)
Light, low-sulphur, ICE-traded. The Gulf's most flexible grade.
API gravity
40.5°
Light
Sulphur
0.76%
Low sour
Exchange
ICE
Futures traded
HeavyLight

ADNOC launched Murban as an ICE futures contract in 2021, making it the Gulf's first exchange-traded benchmark grade. Higher API and lower sulphur than Arab Light makes it processable in a wider range of refineries.

The critical advantage during the crisis: Murban can be exported via Habshan-Fujairah pipeline, bypassing Hormuz. UAE's bypass capacity (~1.5M bbl/d through Fujairah) is the only meaningful Gulf alternative to Hormuz for crude exports.

Main buyers Japan India China South Korea
Fujairah bypass active. Exports continuing via Indian Ocean route. Utilisation near capacity at ~1.5M bbl/d.
Basra Medium
Iraq (SOMO)
97% Hormuz-dependent. Force majeure March 2026. Exports halted.
API gravity
29.7°
Medium heavy
Sulphur
2.95%
Very sour
Pre-crisis
3.3M
bbl/d from Basra
HeavyLight

Iraq's primary export grade — the second-largest single-origin crude stream in Asia-Pacific trade. Very sour with medium-heavy gravity, requiring complex refinery configurations.

100% export halt since March 2026. Refineries in China and India that were running Basra as 20-30% of their feedstock are scrambling to replace a heavy sour grade with limited alternatives. The nearest substitutes are Iranian Heavy (sanctioned), Venezuelan (under sanctions), or Arab Heavy (now at record OSP premium).

Main buyers (pre-crisis) China 34% India 25% South Korea 13%
Force majeure active. Exports halted. Production cut from 3.3M to ~1.4M bbl/d, directed to domestic refineries only.
Kuwait Export
Kuwait (KPC)
Medium sour, Hormuz-dependent. Production severely curtailed.
API gravity
31.4°
Medium
Sulphur
2.52%
Sour
Production
~1.7M
bbl/d · curtailed
HeavyLight

Similar in character to Arab Light but slightly heavier and sourer. Priced at a modest discount to Arab Light — the OSP typically runs $0.50–1.00/bbl below. Kuwait has zero alternative export routes: all oil exits via Mina al-Ahmadi terminal into the Gulf, 100% Hormuz-dependent.

Kuwait ran out of available storage within 14 days of Hormuz disruption and began systematic production curtailments. Storage tanks filled faster than any bypass option could empty them.

Main buyers Japan South Korea India China
Production cut ~810K bbl/d. Storage full. No bypass route. Exports at minimal levels.
Oman / Dubai
Oman · UAE (DME)
The Asian benchmark. OSP calculations for all Gulf grades reference this.
API gravity
33.0°
Medium
Sulphur
1.96%
Sour
Role
DME
Settlement benchmark
HeavyLight

The Dubai Mercantile Exchange settlement price — Oman and Dubai crudes averaged — underpins OSP differentials for all major Gulf producers exporting to Asia. When Aramco says "Arab Light Asia = +$2.50 vs Oman/Dubai," this is the reference.

Currently broken as a benchmark. The Platts assessment that feeds the DME settlement is based on physical transactions — and physical Gulf transactions have collapsed to near-zero since Hormuz disruption. Indian refiners are now challenging the entire 30-year pricing architecture as a result.

Produced by Oman Oil ~800K bbl/d ADNOC Upper Zakum
Benchmark integrity compromised. Near-zero Platts assessment transactions since March 2. India challenging the OSP peg.
Russia / FSU — Hormuz-independent, sanctions-affected
Urals
Russia
Russia's main export blend. Sanctioned in most Western markets. India's discount supply.
API gravity
31.7°
Medium
Sulphur
1.55%
Sour
Discount
~$20
vs Brent · est.
HeavyLight

Similar in specification to Arab Light — medium sour — but exported via Black Sea (Novorossiysk) and Baltic (Primorsk/Ust-Luga). No Hormuz dependency whatsoever. This is why India's diversification into Russian crude since 2022 provides genuine partial insulation from the current crisis.

The discount (~$20/bbl vs Brent) makes it extremely attractive for Indian refiners who can configure for sour crude. The question during the current crisis is whether Russia can physically scale up exports to compensate for Gulf shortfalls — and whether the shadow fleet tankers can handle the volumes.

Main buyers India 35% China 30% Turkey 15%
Western sanctions active. G7 price cap at $60/bbl. Trade rerouted via shadow fleet to India/China. Exports broadly maintained.
ESPO Blend
Russia (pipeline)
East Siberia–Pacific Ocean pipeline. Light, low-sulphur. Unaffected by Hormuz or sanctions.
API gravity
34.8°
Light
Sulphur
0.52%
Low sulphur
Volume
~1.6M
bbl/d to China
HeavyLight

Delivered via pipeline directly to northeast China — no sea transit required, no Hormuz, no Western sanctions enforcement point. China's single most reliable crude supply in the current crisis environment.

Light sweet specification makes it processable in simple refineries — a significant advantage. China does not need its most complex refineries to run ESPO. The 1.6M bbl/d pipeline flow to China is entirely unaffected by the Hormuz closure.

Main buyers China (exclusive)
Fully operational. Pipeline deliveries to China unaffected. 1.6M bbl/d flowing normally. China's anchor supply during crisis.
CPC Blend
Kazakhstan (CPC)
Light sweet Kazakh crude via Black Sea. Key European alternative.
API gravity
44.4°
Very light
Sulphur
0.55%
Low sour
Volume
~1.3M
bbl/d
HeavyLight

Tengizchevroil production (Chevron, ExxonMobil, KazMunayGas) flows via the Caspian Pipeline Consortium to Novorossiysk on the Black Sea, then by tanker to European and Asian markets. No Hormuz dependency.

Very light and relatively low sulphur — processable in simple refineries. European buyers who lost access to Russian Urals have increased CPC offtake. Kazakhstan's chronic overproduction of OPEC+ quotas means supply is consistently available.

Main buyers Italy Netherlands France China
Fully operational. No Hormuz or sanctions exposure. Kazakhstan above OPEC+ quota — supply ample.
North Sea / Western — light sweet, limited volume
Dated Brent
North Sea
The global benchmark. Physical delivery from North Sea fields. Not a Gulf grade.
API gravity
38.1°
Light
Sulphur
0.37%
Sweet
Role
Global
Benchmark
HeavyLight

The ICE Brent futures contract — the world's most traded commodity — is now a basket of North Sea grades (Brent, Forties, Oseberg, Ekofisk, Troll). Physical production is modest (~700K bbl/d net) but the futures price anchors global trade.

The disconnect problem: Brent futures are priced in London for North Sea delivery. Gulf physical crude cannot reach that delivery point when Hormuz is closed. This is why the Arab Light OSP vs Brent spread has blown out to +$11.84 — the benchmark and the physical market are pricing different realities.

Physical buyers Europe (primary) US East Coast Asia (via traders)
Production unaffected. Benchmark integrity stressed — futures disconnected from Gulf physical market. Spread vs Arab Light at record.
Johan Sverdrup
Norway (Equinor)
Europe's largest field. Medium gravity, low sulphur. Growing Asian offtake.
API gravity
28.0°
Medium heavy
Sulphur
0.08%
Very sweet
Production
~755K
bbl/d
HeavyLight

Europe's anchor crude supply. Despite its medium-heavy gravity, its extremely low sulphur content (0.08%) means it can run in simple refineries that would normally require light sweet crude. This is its key competitive advantage — broad refinery compatibility.

Cannot replace Gulf sour crude in complex Asian refineries configured for medium-sour grades — the sulphur removal units in those refineries are not needed for Johan Sverdrup, creating a processing mismatch even if the crude were available in sufficient volume.

Main buyers Europe Poland Germany Asia (growing)
Production normal. No exposure to Middle East disruption. European anchor supply with growing Asian spot demand during crisis.
WTI
United States
Light, sweet US shale blend. Growing export role. No Hormuz exposure.
API gravity
39.6°
Light
Sulphur
0.24%
Sweet
Production
13.3M
bbl/d · US total
HeavyLight

WTI Cushing is the benchmark for US crude. US exports (primarily WTI Midland and WTI Houston) have grown dramatically since the 2015 export ban was lifted, reaching ~5M bbl/d. No Hormuz exposure whatsoever — all export via Gulf of Mexico ports.

The key constraint for Asian buyers: WTI is too light and too sweet for the complex sour-crude refineries in Japan, South Korea, and China that were configured for Arab Medium or Basra. Switching a coking refinery from Arab Heavy to WTI shale is not a simple feedstock swap — it requires significant operational adjustment and yield loss.

Main buyers Europe South Korea Japan (growing) India
Production at record 13.3M bbl/d. Exports rising. US benefits economically from price rise — net exporter position confirmed.
Africa — light sweet, limited Hormuz exposure
Bonny Light
Nigeria (NNPC)
West Africa's premium grade. Light sweet. Popular with Asian buyers during crisis.
API gravity
32.9°
Light
Sulphur
0.14%
Very sweet
Production
~1.3M
bbl/d · volatile
HeavyLight

Nigeria's flagship export grade — light sweet, processable in simple or cracking refineries. Historically priced at a premium to Brent. Nigerian production is chronically below OPEC+ quota due to pipeline theft, sabotage, and infrastructure decay.

During the Hormuz crisis, Bonny Light has attracted strong Asian spot buying from South Korea and Japan as buyers seek light sweet alternatives to UAE grades they can no longer easily access. However, Nigeria's production reliability is a significant constraint on how much volume can actually be committed.

Main buyers Europe India South Korea (growing)
Production below OPEC+ quota. Infrastructure reliability limits volume commitments. Spot premiums rising due to Asian demand surge.
Saharan Blend
Algeria (Sonatrach)
Mediterranean light sweet. Europe's preferred alternative to Gulf grades.
API gravity
46.4°
Very light
Sulphur
0.09%
Very sweet
Production
~1.3M
bbl/d total
HeavyLight

One of the world's lightest crudes — 46° API and nearly sulphur-free. Exported directly to Mediterranean refineries via pipeline and tanker, zero Hormuz exposure. Europe's original light sweet alternative.

Its very light specification means it cannot substitute for medium-heavy Gulf grades in complex refineries. Algerian production is declining due to mature field depletion. Volume constraints limit its role as a crisis-period replacement.

Main buyers Italy France Spain UK
Production stable but declining. No Hormuz exposure. Mediterranean route unaffected. Increasing spot demand from crisis-period Europe.
Sources: EIA crude assay database · Saudi Aramco product specifications · ADNOC Murban crude assay · S&P Global Platts crude oil assay database · IEA Oil Market Report March 2026 · BP Statistical Review 2025 · Argus Media crude assessments · March 2026 · All specifications indicative