“Cummins generations” follow the generations of the Dodge and Ram heavy-duty pickups the engine came in. The 1st gen ran from 1989 to 1993, the 2nd gen from 1994 to 2002, the 3rd gen from 2003 to 2009, the 4th gen from 2010 to 2018 and the 5th gen from 2019 on. The engine changed along the way from the mechanical 12-valve 5.9 to the electronically controlled 24-valve, then common rail and finally the 6.7.
Cummins generations at a glance
| Generation | Ram model years | Engine | Fuel injection |
|---|---|---|---|
| 1st gen | 1989-1993 | 5.9L 12-valve | Bosch VE rotary pump (mechanical) |
| 2nd gen | 1994-2002 | 5.9L 12-valve (1994-1998), then 5.9L 24-valve (1998.5-2002) | Bosch P7100 inline pump (12-valve); VP44 electronic rotary pump (24-valve) |
| 3rd gen | 2003-2009 | 5.9L common rail (2003-2007), then 6.7L (2007.5-2009) | High-pressure common rail |
| 4th gen | 2010-2018 | 6.7L | High-pressure common rail |
| 5th gen | 2019 on | Updated 6.7L | High-pressure common rail |
1st gen Cummins (1989-1993)
The first Cummins-powered Dodge pickups used the 5.9-liter 12-valve inline six with a mechanical Bosch VE rotary injection pump. Simple and tough, these trucks started the Cummins reputation for durability.
2nd gen Cummins (1994-2002)
The redesigned Ram kept the 12-valve 5.9 at first, now with the Bosch P7100 inline pump that made the 1994-1998 12-valve trucks so popular with enthusiasts. Midway through 1998 the 24-valve ISB arrived with the electronically controlled VP44 pump. Our 12 valve vs 24 valve vs common rail guide compares them.
3rd gen Cummins (2003-2009)
The 3rd gen brought the 5.9 common rail engine, with injection pressure controlled electronically and fed by a Bosch CP3 pump; see CP3 pump. Midway through 2007 the 6.7-liter replaced the 5.9, together with a diesel particulate filter.
4th gen Cummins (2010-2018)
The 4th gen Ram heavy duty kept the 6.7. Turbos changed from the Holset HE351VE to the HE300VG for 2013, when Ram heavy-duty pickups also added selective catalytic reduction with diesel exhaust fluid. Specs and oil capacity are in our 6.7 Cummins specs guide.
5th gen Cummins (2019 on)
The 5th gen Ram heavy duty received a revised 6.7 with higher ratings, especially in high-output form, and the fuel system moved to Bosch’s CP4 family of pumps.
Which generation do you have?
The model year usually tells you, with two exceptions: 1998 trucks can be 12-valve or 24-valve depending on build date, and 2007 trucks can have the 5.9 or the 6.7. Check the engine label or ask us with your VIN.
Cummins parts we carry by generation
- 3rd gen 5.9 common rail: D&J short blocks, long blocks and the Ready Run engine on our 5.9 Cummins engines page.
- 3rd, 4th and 5th gen 6.7: D&J engines by model-year range on our 6.7 Cummins engines page, and Fleece VGT turbos for 2007.5-2012 and 2013-2018 on our 6.7 Cummins turbo page.
- 2009-2020 Ram 2500/3500: the Red-Head steering gear box; see bad steering box symptoms.
- Transmissions such as the 47RE, 48RE, 68RFE and Aisin AS69RC: see Dodge and Ram transmissions.
We do not carry 12-valve or 24-valve engines. For how Cummins compares with other diesels, read Cummins vs Duramax vs Powerstroke.
More guides: 48RE problems · 68RFE problems · 5.9 Cummins problems · 48RE vs 68RFE · how long diesel engines last · 5.9 vs 6.7 Cummins · how long a Cummins lasts · 5.9 Cummins specs · Cummins killer dowel pin.
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