6.0L Power Stroke vs. 5.9L Cummins vs. 6.6L Duramax

 

 

6.0L Power Stroke

5.9L Cummins ISB

6.6L Duramax LBZ

Production Years:

2003 - 2007

1998 - 2007.5

2006 - 2007.5

Manufacturer:

International

Cummins

Isuzu

Block/Head Material:

Iron/Iron

Iron/Iron

Iron/Aluminum

Configuration:

V-8

Inline 6

V-8

Displacement:

6.0 liters, 365 cubic inches

5.9 liters, 359 cubic inches

6.6 liters, 403 cubic inches

Compression Ratio:

18.0:1

16.3:1 (17.3:1 in HO version)

16.8:1

Bore x Stroke:

3.74 x 4.13 inches

4.02 x 4.72 inches

4.06 x 3.90 inches

Injection System:

Hydraulic electronic unit injection (HEUI)

Bosch rotary injection pump. Switched to high pressure common rail injection in 2003

High pressure common rail, CP3 injection pump

Aspiration:

Variable Geometry Turbocharger (VGT)

Holset Turbocharger

Variable Geometry Turbocharger (VGT)

Valvetrain:

Overhead cam, 4 valves per cylinder

Overhead valve, 4 valves per cylinder

Overhead valve, 4 valves per cylinder

Weight:

approx. 966 lbs

1,150 lbs (approx.)

835 lbs (approx.)

Peak Horsepower:

325 hp @ 3,300 RPM

325 hp @ 2,900 RPM (high output model)

360 hp @ 3,200 RPM

Peak Torque:

570 lb-ft @ 2,000 RPM

610 lb-ft @ 1,600 RPM (high output model)

650 lb-ft @ 1,600 RPM

Reputation:

Stock torque to yield (TTY) head bolts proved to be a weak link. The overall engine design suffices, though the Power Stroke experienced severe reliability issues. Overall a strong performer with good fuel economy. The Ford TorqShift 5-speed automatic has a positive reputation .

Brute strength, builds torque at low engine speeds. More turbo lag than Ford & GM diesels equipped with variable geometry turbochargers. Medium duty engine in light duty trim. Chrysler's 48RE automatic transmission is the weak link.

The LBZ is considered the "hot rod" of Duramax diesels due to its power potential with aftermarket tuning and lack of emissions equipment to complicate matters. The Allison 1000 6-speed automatic transmission remained a strong selling point for the Duramax diesel.