5.9L Cummins 12v

6BT Cummins Turbodiesel Specs, Info, & More

The 6BT Cummins was introduced in 1984 as an engine for agricultural equipment. In 1989, Dodge teamed with Cummins to offer the 5.9L Cummins in their 3/4 and 1 ton Dodge Ram pickups. The 12v Cummins quickly became a popular alternative to Dodge's V-8 gas engines, as the diesel generated nearly double the torque at low engine speeds and provided a significant increase in fuel economy, especially loaded down. The 12v Cummins, or 6BT, received an intercooler in 1991, and the P1700 injection pump replaced the VE for the 1994 model year. The 12v Cummins is arguably the most popular Cummins produced to date amongst Dodge Ram owners. It was produced through the 1998 model year, where it was eventually phased out in favor or a more emissions friendly 24 valve version, the 5.9L ISB. The 6BT has been used in a variety of applications, including light and medium duty trucks, agricultural equipment, and construction machinery.

5.9L 12v Cummins Specs

Production Years:

1989 - 1998


Inline 6 cylinder


359 cubic inches, 5.9 liters

Bore x Stroke:

4.02" x 4.72"

Cylinder Head Material:

Cast iron

Engine Block Material:

Cast iron

Firing Order:


Compression Ratio:

17.0 : 1


Direct Injection
• Bosch VE44 rotary injection pump (1989-1993)
• Bosch P7100 injection pump (1994-1998)


Holset turbocharger, intercooler introduced mid-1991 model year


OHV, 2 valves per cylinder, solid lifter camshaft

Valve Lash (Clearance):

Exhaust Valves:

0.020" (must be checked with engine cold)

Intake Valves:

0.010" (must be checked with engine cold)


Approx. 1,100 lbs dry

Oil Capacity:

12 quarts

Governed Speed:

2,700 rpm


160 - 215 HP @ 2,500 rpm


400 - 440 lb-ft @ 1,600 rpm


12v Cummins Dimensions







12v Cummins Horsepower & Torque by Model Year

Note - power ratings only applicable to Dodge pickup applications.

Model Year



1989 - 1993

160 hp @ 2,500 rpm

400 lb-ft @ 1,600 rpm

1994 - 1995

• 160 hp @ 2,500 rpm (auto trans)
• 175 hp @ 2,600 rpm (manual trans)

• 400 lb-ft @ 1,500 rpm (auto trans)
• 420 lb-ft @ 1,500 rpm (manual trans)

1996 - 1998

• 180 hp @ 2,500 rpm (auto trans)
• 215 hp @ 2,600 rpm (manual trans)

• 420 lb-ft @ 1,500 rpm (auto trans)
• 440 lb-ft @ 1,500 rpm (manual trans)

12v Cummins Horsepower/Torque vs Model Year Graph

The Cummins 6BT was introduced in 1984 as an application in Case agricultural equipment. The engine uses a heater grid mounted beneath the air horn to assist with cold starting. This method is an alternative to the standard glow plug system, which relies on an individual glow plug mounted within the combustion chamber of each cylinder. If an engine is difficult to start, especially in extremely cold conditions, the heater grid is likely the culprit. The 12v Cummins has developed a cult following in the diesel motorsports scene, due in part to its simplicity, reliability, strength, and performance potential. Its relatively short width and fully mechanical design make it a popular choice for engine swaps and diesel conversions, as it is amongst the easiest engines to shoehorn into a compact engine bay and aftermarket support is high. The 12 valve's Achilles heel is what has come to be known as the "killer dowel pin" - a dowel pin pressed into the front of the engine block during assembly commonly backs out of its hole over time, which, in a worst case scenario, can wedge itself between the timing gears and create a chain of events that ultimately results in catastrophic engine failure. Aftermarket solutions have remedied the problem by creating products that secure the dowel pin in place so that it may not vibrate loose.