Gross Refining Margins (GRM) and India's Refining Sector

A refinery is a giant factory that turns crude oil (the thick black oil pumped from the ground) into products we use, like petrol, diesel, jet fuel and cooking gas. The Gross Refining Margin (GRM) is the money a refinery earns on each barrel of crude it processes. It equals the total value of all the products made from one barrel, minus the cost of that barrel of crude. It is usually shown in US dollars per barrel (one barrel is about 159 litres).

Why does the GRM matter?

Think of a juice shop. The shop buys oranges, makes juice, and sells it. The gap between the juice price and the orange cost is its gross earning. A refinery works the same way. Crude is its "orange" and fuels are its "juice". The GRM tells us how profitable refining is at a given time.

Governments watch it because a very high GRM means refiners are earning unusually large profits. Investors watch it because it drives the profits of oil companies. Policymakers watch it because it affects fuel exports, fuel prices and tax revenue.

How does a refinery make products?

A refinery works in steps:

1. Distillation: Crude is heated. Different parts boil at different temperatures and separate. Light parts (like LPG and petrol) rise to the top. Heavy parts (like fuel oil and bitumen, used for roads) stay at the bottom.
2. Cracking: Heavy, low-value parts are "cracked", that is, their big molecules are broken into smaller ones using heat, pressure and chemicals called catalysts. This turns cheap heavy oil into costly petrol and diesel. Common units are fluid catalytic crackers and hydrocrackers.
3. Upgrading and cleaning: Units like reformers improve petrol quality, and other units remove sulphur so fuels meet clean-fuel standards such as BS-VI.

The more of these advanced units a refinery has, the more high-value products it can squeeze out of each barrel.

What is a crack spread?

The word "crack" comes from the cracking process. A crack spread is the price gap between one product and crude oil. For example, the diesel crack is the price of a barrel of diesel minus the price of a barrel of crude. The petrol crack is the same for petrol. A popular combined measure in the US is the 3-2-1 crack spread.

It assumes 3 barrels of crude make 2 barrels of petrol and 1 barrel of diesel. The GRM is wider: it adds up the value of all the products a refinery actually makes (including low-value ones like fuel oil) and subtracts the actual crude cost.

What decides how high the GRM is?

• Product prices vs crude prices: If a war or shortage pushes diesel prices up faster than crude, the diesel crack and the GRM jump.
• Type of crude used: Crude can be light (flows easily, gives more petrol and diesel) or heavy (thick, gives more heavy products). It can be sweet (low sulphur, commonly below 0.5%) or sour (high sulphur). Heavy, sour crude is cheaper to buy. A refinery that can handle it earns more.
• Complexity of the refinery: A complex refinery has more cracking and upgrading units. It can process cheap crude and still make costly fuels.
• Discounts on crude: Buying crude at a discount, for example Russian crude after 2022, directly raises the GRM.
• Timing: Refiners buy crude weeks before they sell products. If prices move in between, the "inventory" gain or loss changes the reported GRM.

How is refinery complexity measured?

The Nelson Complexity Index (NCI) gives every refinery a score. It was developed by Wilbur Nelson in a series of articles in the Oil & Gas Journal in 1960-61. The basic crude distillation unit gets a score of 1. Every advanced unit adds points based on its cost compared with the distillation unit. A higher score means the refinery can make more valuable products from each barrel.

Reliance Industries' Jamnagar refinery in Gujarat has an NCI of about 21.1, among the highest in the world. Jamnagar is widely described as the world's largest refining complex at a single site.

What benchmark is used in Asia?

Indian refiners usually compare their GRM with the Singapore complex GRM. It is a standard margin for a typical complex refinery in Singapore, Asia's main oil trading hub. A company that earns more than the Singapore GRM is doing better than an average Asian refiner. Private refiners with very complex plants have often earned above this benchmark. Many older public sector refineries, which are simpler, have often earned below it.

India's refining sector: the key facts

• India has about 23 refineries, run by public sector companies, private companies and joint ventures.
• Installed refining capacity was about 256.8 million tonnes per annum (MMTPA) as of 1 April 2024, according to the Petroleum Planning and Analysis Cell (PPAC) of the Ministry of Petroleum and Natural Gas. As of July 2026, the government put it at around 270 MMTPA.
• The biggest refiners by capacity are Indian Oil Corporation (IOCL), about 70.3 MMTPA, and Reliance Industries, about 68.2 MMTPA, followed by BPCL (about 35.3 MMTPA) and HPCL (about 23.2 MMTPA) (as of April 2024).
• India imports most of its crude. Its crude oil import dependence was about 88.2% in 2024-25 (PPAC, provisional).
• Even so, India refines more fuel than it uses, so it is a large exporter of petroleum products, mainly diesel and ATF. Europe became the top destination after 2022, with the Netherlands as a major hub.
• In 2024, the government set a goal of 450 MMTPA by 2030. In July 2026, the petroleum minister spoke of reaching about 309.5 MMTPA by 2030 and 400-450 MMTPA over the longer term.

How does the GRM connect to fuel prices and taxes in India?

Petrol prices were freed from government control in June 2010, and diesel prices in October 2014. Since 16 June 2017, oil marketing companies revise petrol and diesel prices daily, in principle. So, in theory, international product prices flow into Indian pump prices. When world fuel prices shoot up, refiners can earn much more by exporting.

This raises two worries: fuel shortages at home and unusually large profits. The government's answer is the windfall tax on exports (SAED). It is set every two weeks based on cracks and margins: high cracks lead to a high levy, low cracks to a low or zero levy.

Commonly confused concepts

• GRM vs crack spread: A crack spread is for one product (diesel minus crude). The GRM covers the whole basket of products a refinery makes.
• GRM vs net refining margin: The GRM is before costs. The net refining margin is the GRM minus the refinery's own running costs, like power, staff and maintenance.
• Refining margin vs marketing margin: Refining margin is earned by making fuel from crude. Marketing margin is earned by selling fuel at petrol pumps. Companies like IOCL, BPCL and HPCL earn both.
• Light vs heavy, sweet vs sour crude: Light/heavy is about density (how thick the oil is). Sweet/sour is about sulphur content. They are two separate scales.
• Refining capacity vs throughput: Capacity is the most a refinery can process in a year. Throughput is what it actually processed.

Issues, criticism and the way forward

• Volatility: GRMs swing sharply with wars, sanctions and shipping disruptions. This makes refiners' profits, and the government's windfall revenue, hard to predict.
• Fairness of windfall taxes: Refiners argue that taxing high margins in good times is unfair when nobody compensates them for losses in bad times. They also say frequent rate changes make long-term export contracts hard. The government's view is that sudden, unearned profits should be shared with the public, and domestic supply must come first.
• Import dependence: With about 88% of crude imported, India's refining profits and fuel security depend heavily on foreign supply and prices.
• Low complexity of older refineries: Some older public sector refineries earn lower margins. Upgrading them needs large investment.
• Energy transition: As the world moves to electric vehicles and clean fuels, long-term demand for petrol and diesel may fall. Experts suggest more petrochemical integration (making plastics and chemicals from oil), cleaner fuels and better crude sourcing to keep refineries profitable.

Concepts to Know

• Barrel: The standard unit for oil. One barrel is about 159 litres.
• MMTPA: Million metric tonnes per annum, a measure of how much crude a refinery can process in a year.
• Catalyst: A substance that speeds up a chemical reaction without being used up.
• Petroleum Planning and Analysis Cell (PPAC): A body under the Ministry of Petroleum and Natural Gas that collects and publishes data on oil and gas.
• Oil marketing companies (OMCs): Companies like IOCL, BPCL and HPCL that refine fuel and sell it through petrol pumps.
• Inventory gain: Extra profit a refiner makes when product prices rise after it has already bought its crude at a lower price.