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 optimized for high energy output, reliable ignition, and long engine life.
This grade provides the best balance of power, efficiency, and cost, making it the preferred fuel for on-road and off-road compression-ignition engines operating under normal climatic conditions.
Physical & Chemical Properties
Density: 0.82 – 0.85 g/cm³
API Gravity: 30 – 40° API
Higher density delivers greater energy per liter compared to lighter diesel grades
Viscosity @ 40°C: 1.9 – 4.1 cSt
Ensures proper atomization, injector lubrication, and spray pattern
Cetane Number: 40 – 55
Shorter ignition delay, quieter operation, improved cold starting, reduced white smoke
Energy Content: ~137,000 – 139,000 BTU/gal
Delivers strong torque and fuel economy in heavy-duty engines
Combustion & Performance
Designed for compression-ignition engines
Stable and controlled combustion
Supports long run hours and heavy-duty cycles
Optimized for high-speed and high-torque diesel engines
Refining & Processing
Derived from middle-distillate crude fractions
Boiling range: 200°C – 350°C
Produced via atmospheric distillation, vacuum distillation, and hydrocracking
Hydrotreating (ULSD):
Sulphur reduced using hydrogen under pressure
ULSD (on-road): ≤15 ppm sulphur
Industrial/off-road grades: up to 500 ppm
Additive Blending:
Cetane improvers
Lubricity enhancers
Cold-flow improvers
Detergents and corrosion inhibitors
Emissions & Environmental Profile
Low sulphur grades reduce SO₂ and particulate emissions
Compatible with DPF, SCR, and EGR systems
Lower smoke and HC emissions compared to heavier fuels
Applications
Passenger cars, buses, and trucks
Long-haul logistics vehicles
Railway locomotives (non-electrified)
Diesel generators and industrial engines
Construction, mining, and drilling equipment
Agricultural machinery
Storage & Handling
Store above cloud point temperature
Shelf life: 6 – 12 months (extendable with stabilizers)
Clean, dry tanks required
Protection from moisture to avoid microbial growth
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
Best fuel economy among standard diesel grades
Excellent engine lubrication and protection
Widely available and globally standardized
Compatible with most diesel engines
Limitations
Less suitable for extreme cold without additives
Wax gelling at low temperatures
Requires ULSD compliance for modern engines
Industry Standards
ASTM D975 (USA)
EN 590 (Europe)
IS 1460 (India)
ISO 8217 (Marine & Industrial)