Fuel & DEF Verified Factory Specs

Diesel Brake Specific Fuel Consumption (BSFC) Engineering Calculator

Calculate and analyze heavy commercial diesel Brake Specific Fuel Consumption (BSFC) in lb/hp·hr and g/kW·h. Benchmark engine thermal efficiency across Cummins, Detroit, and Caterpillar.

Engine Rated Horsepower (HP)

Average Engine Load Factor

Average Cruise Speed

MPH

SCR DEF Dosing Rate

Fuel Burn Rate (GPH)

10.57 gal/hr

40.01 Liters/hour

Calculated Fuel Mileage

6.1 MPG

At 65 MPH sustained cruise

DEF Injection Rate

0.317 gal/hr

3% of diesel consumption

DEF Range Per Gallon

205 miles/gal

~3075 miles on 15-gal tank

Commercial Heavy Diesel BSFC Benchmarks

Brake Specific Fuel Consumption measures how efficiently an engine turns fuel mass into mechanical crankshaft work:

Engine Model	Rated HP	Optimal RPM	BSFC (lb/hp·hr)	Metric BSFC (g/kW·h)
Cummins X15 Efficiency	500 HP	1150 RPM	0.325	198 g/kW·h
Detroit DD15 Gen 5	505 HP	1200 RPM	0.328	200 g/kW·h
Cat C15 6NZ	550 HP	1400 RPM	0.345	210 g/kW·h
PACCAR MX-13	455 HP	1100 RPM	0.33	201 g/kW·h

Related Heavy Diesel Engineering Tools

Cross-reference other factory specifications and diagnostic tools for commercial diesel engines:

Pillar 3 →

Valve Lash & Overhead

Intake, exhaust, & Jake brake clearances.

Pillar 1 →

Oil & Coolant Sump

Standard vs deep pan fill volumes.

Pillar 4 →

Head Bolt Torque

Torque-to-yield angle stages & sequences.

Pillar 2 →

SPN Fault Code Lookup

J1939 fault diagnostics & sensor pins.

Technical Reference Citation: SAE J1995 Engine Power Test Code (Gross) & ISO 3046 Reciprocating Internal Combustion Engines

View Engineering Methodology & Standards →