Dodge-Cummins FAQ

Answers to Frequently Asked Questions About Cummins Turbodiesels

When was Cummins founded?

Clessie L. Cummins founded the Cummins Engine Co. (now Cummins Inc.) in 1919, building small diesel engines. These early engines were by-and-large defective, and it was not until 1930 that the company produced its first commercially successful diesel engine. The reputation of the Cummins brand has since grown to become synonymous with reliability and longevity.

What are the benefits of an inline cylinder arrangement, as opposed to a V cylinder arrangement?

Inline 6 engines are inherently balanced (but this does not apply to all inline engines). The result is smooth operation, minimal vibration, and steady harmonic transitions between light and heavy engine loading (particularly at low engine speeds). The fact that the straight 6 engine is naturally balanced allows for scalability, which is one of the reasons why you'll see such similarity between large and small engines of the same engine family.

When did Dodge start offering the Cummins in its pickups?

1989 was the first model year that Dodge offered a Cummins Turbodiesel. The original 6BT (5.9) was rated at 160 hp and 400 lb-ft of torque. At this time, Cummins' closest competitor in the market was International/Navistar, whose 7.3L IDI produced 185 hp and 360 lb-ft of torque in Ford 3/4 and 1 ton pickups. Detroit's 6.2L, used in GMC and Chevrolet pickups, trailed by a large margin with 130 hp and 240 lb-ft of torque for the 1989 model year. The Big 3 have since been competing profusely for market share.

What are the Dodge Cummins "Generations"?

"Gen" refers to the generation of Cummins engine in regards to Ram pickups. The following chart might help better understand how Cummins describes the various generations:


Model Years


Generation 1

1989 - 1993

1st Gen, 5.9L 12v Cummins, VE44 rotary style injection pump

Generation 2

1994 - 2002

2nd Gen, 5.9L 12v Cummins 1994 - 1998, P1700 injection pump. 5.9L 24v Cummins 1998.5 - 2002, electronically controlled VP44 injection pump.

Generation 3

2003 - 2009

3rd Gen, 5.9L 24v Cummins, common rail injection, 2003 - 2007. 6.7L Cummins, 2007.5 - 2009.

Generation 4

2010 - current

4th Gen, 6.7L Cummins

What does 6BT stand for?

The acronym "6BT", which denotes the 5.9L 12v Cummins (1989 - 1998 model years), stands for 6 cylinder, "B series", turbocharged. The Cummins "B series" is a family of inline cylinder diesel engines including 4 and 6 cylinder models.

What does ISB stand for?

The acronym "ISB" is short for "Interact System B", where "Interact System" denotes that the engine is controlled electronically (opposed to mechanically), and the B refers to the fact that the engine is a Cummins "B series" design. "Cummins ISB" is typically used in reference to the 5.9L 24 valve Cummins, successor of the mechanical 6BT (12 valve). It was available from 1998 to 2007 model years, then replaced by the 6.7L ISB.

Does Ford own Cummins?

This is a rumor that has taken years to squash, but there are still those that hold this to be true; it is false. Ford does not, and has never owned Cummins. This rumor likely spawned from the fact that Ford was, at one period of time, a Cummins shareholder. Even then, Ford did not own enough of Cummins' stock to participate in or influence the company's decisions. Ford has historically engaged in business dealings with Cummins, as Cummins' engines have been offered in Ford's medium duty vehicle lineup off-and-on throughout the years.

What is a "common rail Cummins"?

A common rail (CR), more specifically a high pressure common rail, is an injection type that uses a shared delivery tube to provide fuel to each individual injector. The rail is pressured via a high pressure injection pump, and each injector is individually fired electronically. This is in contrast to a mechanical system, which uses an injection pump to feed high pressure fuel to each injector through individual lines (a 6 cylinder engine would therefore have 7 fuel lines - one low pressure inlet and one high pressure outlet for each injector). The common rail is a far superior design, and is the injection type of choice for all modern diesels.

Why don't Cummins diesels have glow plugs?

If someone asks where the glow plugs are on your Cummins are, they are playing a joke on you. The Cummins uses a single heater grid located in the intake of the engine in place of a traditional glow plug system, which would require an individual glow plug for each cylinder. The purpose of the heater grid is exactly the same as that of glow plugs - to warm the incoming air charge during cold starts. So no, your Cummins does not have glow plugs.