Grade 2-D Diesel, commonly known as No. 2 Diesel, is the global standard diesel fuel used across transportation, power generation, agriculture, mining, construction, and industrial sectors. It is a middle-distillate petroleum product refined from crude oil and optimized for high energy output, reliable ignition, and engine durability.
This grade offers the best balance of power, efficiency, and cost, making it the preferred diesel fuel for on-road and off-road compression-ignition engines operating under normal climatic conditions.
Physical & Chemical Properties
Density & API Gravity
Density: 0.82 – 0.85 g/cm³
API Gravity: 30 – 40° API
Higher density results in greater energy per liter compared to lighter diesel grades.
Viscosity @ 40°C: 1.9 – 4.1 cSt
Ensures:
Proper fuel atomization
Efficient injector spray pattern
Adequate lubrication for fuel system components
Cetane Number: Typical Range : 40 – 55
Higher cetane:
Shorter ignition delay
Quieter engine operation
Improved cold starting
Reduced white smoke
Energy Content: ~137,000 – 139,000 BTU/gal
Delivers strong torque and fuel economy especially in heavy-duty engines
Combustion & Performance
Designed for compression ignition engines
Produces stable and controlled combustion
Supports:
Long engine run hours
Heavy load operations
Continuous duty cycles
Optimized for high-speed and high-torque diesel engines
Refining & Processing Details
Refining Process
Derived from middle-distillate crude fractions
Boiling range: 200°C – 350°C
Produced via atmospheric distillation, vacuum distillation, and hydrocracking(for quality enhancement)
Hydrotreating (ULSD Processing):
Sulphur reduced using hydrogen under pressure
Final sulphur content:
ULSD: ≤15 ppm (on-road fuel)
LSD/Industrial grades: up to 500 ppm (off-road, marine, export)
Additive Blending:
Cetane improvers
Lubricity enhancers
Cold-flow improvers
Detergents and corrosion inhibitors
Anti-foam and corrosion inhibitors
Emissions & Environmental Profile
Low sulphur grades reduce SO₂ and particulate emissions
SO₂ emissions
Particulate matter (PM)
Compatible with
Diesel Particulate Filters (DPF)
Selective Catalytic Reduction (SCR)
Exhaust Gas Recirculation (EGR)
Produces:
Lower CO and HC emissions than heavier fuel oils
Lower smoke compared to low-cetane diesel fuels
Applications & End Uses
Transportation:
Cars, SUVs, buses, trucks
Long-haul logistics vehicles
Railway locomotives (non-electrified routes)
Industrial & Power :
Diesel generator sets
Industrial engines
Construction machinery
Mining and drilling equipment
Agriculture:
Tractors
Harvesters
Irrigation pump sets
Marine (Non-IMO Fuel):
Inland vessels
Fishing boats
Small marine engines (where permitted)
Storage & Handling Characteristics
Storage temperature: Above cloud point
Shelf life: 6–12 months (can be extended with stabilizers)
Requires:
Clean, dry tanks
Protection from moisture
Periodic filtration to prevent microbial growth
Susceptible to:
Wax crystallization in cold climates
Microbial contamination if water is present
Comparison with Other Diesel Grades
| Parameter | Grade 1-D | Grade 2-D | Grade 4-D |
|---|---|---|---|
| Energy Content | Low | High | Very High |
| Viscosity | Low | Moderate | Very High |
| Cold Weather Use | Excellent | Moderate | Poor |
| Engine Type | Light-duty | Standard & Heavy-duty | Large stationary |
| Cost | Higher | Economical | Lower |
Advantages of Grade 2-D Diesel
Best fuel economy among standard diesel grades
Strong lubrication for engine protection
Widely available and globally standardized
Suitable for most diesel engines without modification
Balanced emissions and performance profile
Limitations
Less suitable for extreme cold climates without additives
Can gel at low temperatures
Slightly higher emissions compared to alternative fuels (biodiesel, LNG)
Requires ULSD compliance for modern emission-controlled engines
Industry Standards
ASTM D975 (USA)
EN 590 (Europe)
IS 1460 (India)
ISO 8217 (Marine & Industrial)