The 5.9 Cummins was produced in two different variations by Dodge from 1989 until 2007. The first generation, known as the 6BT or 5.9 Cummins 12v, was produced from 1984 until 1998. It produced 160-230hp and 400-440lb-ft. of torque. The ISB 5.9 Cummins 24v entered in mid-year 1998 and was phased out after 2007 for the 6.7 Cummins. It was initially offered with 235hp and 460lb-ft. but retired producing 325hp and 610lb-ft. of torque.
While both versions of the 5.9 Cummins offered solid power for their times, they are significantly underpowered compared to the diesel engines of today. Fortunately, a handful of performance mods can easily liven up the 5.9 Cummins and give it more life. One of the best upgrades is a 5.9 Cummins cold air intake. An upgraded intake system will increase air flow which allows for a more efficient turbo and therefore adds power.
This guide will discuss the performance benefits of cold air intakes, the different types of intakes available, and provide a few of our favorite 5.9 Cummins intake systems.
If you’re interested in further intake upgrades, check out our 5.9 Cummins Intake Manifold Upgrade.
5.9 Cummins Cold Air Intake Performance Benefits
The biggest benefit of an upgraded intake for the 5.9 Cummins is the increase in horsepower and torque. However, the benefits of an intake go far beyond just the power levels. A cold air intake will increase air flow by about 30%-50% over the stock intake. The improved airflow allows the turbo to spool more quickly with less restriction which also improves throttle response. Additionally, an intake can even increase gas mileage by about 1-2mpg.
Benefits of adding a cold air intake to the 5.9 Cummins include:
- 5-10whp+ gains
- 10-20wtq+ gains
- 30%-50% increase in air flow
- Better throttle response
- Faster turbo spool
- 1-2mpg increases
- Cool turbo and intake noises
Cold air intake power gains can vary on a 5.9 Cummins depending on what other mods you have. A completely stock 5.9 will probably see power gains on the low end of both the ranges. Alternatively, a tuned 5.9 Cummins will likely see power gains towards the top end of the range as the benefits of an upgraded intake increase substantially with a tune.
When a turbocharged engine is tuned the boost or psi levels increase. This means the air is further compressed. The more air is compressed the less space it consumes. Therefore when boost is increased you need to increase the volume of air you are sending to the turbo as it needs to compress more air. This is where the stock intake can become restrictive and why power gains are better on tuned engines.
Upgraded intakes also tend to increase horsepower and torque in the low-end of the power curve. The power numbers we quoted are for peak power gains. So while a stock 5.9 Cummins might show zero peak power gains you will likely see power gains throughout the low-end of the power curve.
5.9 Cummins Cold Air Intakes vs. Other Intakes
Upgraded intake systems are predominantly called and referred to as “cold air intakes”. While it’s the most commonly used term, it is sort of inaccurate when it comes to 5.9 Cummins upgraded intake systems. Cold air intake reroute the intake filter to a part of the engine bay that receives colder air, usually within the lower section of the front bumper. The purpose being to draw in colder air.
Other common terms are ram air systems, performance intake systems, and so on. Virtually all intakes for the 5.9 Cummins are technically ram air intakes. Ram air intakes keep the same stock air filter location and instead focus on reducing restriction and improving airflow rather than drawing in colder air.
At the end of the day, the type or name of the intake doesn’t matter. All intake do the same thing. However, what does matter is whether you choose an open or a closed intake system.
Open vs. Closed Intakes
The only important decision in choosing an intake for your 5.9 Cummins is whether you get an open or closed intake. As the name suggests, open intakes have the air filter directly exposed to the engine bay whereas closed intake have the filter within a box. You’ll also notice some “open” intakes that use heat shields to try to protect the air filter from engine bay heat.
Open intakes will usually flow about 20% more air than closed intakes as they have less restriction. This results in open intakes probably better performance and power gains. Closed intakes do pull in slightly cooler air since they aren’t directly exposed to engine heat. However, intake air temps don’t really matter on turbo engines as it doesn’t affect the intercoolers ability to cool the air before entering the combustion chamber.
The one benefit (or downside) to closed intakes is that they are quieter. You get a lot less turbo and intake induction noises. We love the sound of open intakes, but if you don’t want as much noise then closed intakes are they way to go.
On to heat shields. We don’t think they are necessary. Heat shields do shield the air filter from some engine heat but ultimately it isn’t enough for it to matter. If it gives you piece of mind, go for it, but otherwise it seems like a waste of money to add the extra material to the intake system.
Overall, we prefer open intakes due to the additional air flow and better power gains they provide.
Best 5.9 Cummins Cold Air Intakes
We recommend open intakes but we will mention a few of the best closed 5.9 Cummins intakes as well for those wanting less noise. Just as a general note, intake fitment varies by model year. Most 1994-2002 models have the same fitment, and same for 2003-2007 models.
There are dozens of great options on the market so this isn’t a complete list. This is simply a few of our different favorites. The most important thing is selecting an intake with a good filter. All reputable name brands will use high quality intake filters, such as S&B filters. On the other hand, most cheap Amazon and eBay intakes will use cheap China filters.
1) Sinister Diesel 5.9 Cummins Cold Air Intake
Sinister Diesel manufactures intake kits for both the first gen and second gen 5.9 Cummins. Sinister is known for manufacturing very high quality products that look great under the hood. They make their own custom air filters which in part contributes to their price point.
For those of you with a 12V, the price is a bit favorable near the $300 mark. However, for 24v owners the intakes run closer to the $450 price point which is a bit steep for an open intake. However, you get what you pay for and the quality here is top notch.
Both of their intake systems are true open intakes with simply an air filter and piping. They don’t have heat shields (which we don’t think are really worth it) and therefore will provide the most air flow and performance benefit.
Price: ~$300 for 12v’s, $425-$450 for 24v’s
What We Like: Awesome looking under the hood and high quality. True open intake for the best performance
What We Don’t Like: The price. It’s pretty expensive for a piece of piping and an air filter. The lack of box or heat shields should leak to lower costs, right?
2) 5.9 Cummins S&B Closed Intake System
S&B is one of the biggest names in diesel performance, and air filters. The majority of aftermarket Cummins intakes use S&B filters, with the exception of Sinister Diesel. If you are looking for a closed intake system, this is one of the best bang-for-the-buck’s on the market.
Both coming in at $349, the 24v intake comes in with a 42% air flow improvement, and the 12v has a 37% improvement over the stock system. While this is still less of an increase compared to an open intake, it should suffice for anyone who isn’t looking for massive power levels.
If you want a closed intake, this is our recommendation. We would still recommend an open intake despite the solid air flow gains from the S&B intake, but this is a good option for those wanting a closed intake.
What We Like: For a fully closed intake, this is about as good as price gets. It’s a big brand with a great reputation
What We Don’t Like: The airbox is big and restrictive compared to an open intake. Less airflow = less power gains
5.9 Cummins Upgraded Intake Summary
The 5.9 Cummins offered solid performance from the factory, when these trucks were built. However, in by today’s standards they are underpowered. Fortunately, it is pretty easy to extract power out of the 5.9 Cummins. And not to mention these engines are pretty bulletproof.
A cold air intake is one of the best mods you can make to the 5.9 Cummins. While peak power gains will be very modest on a stock truck it will help increase power at the low-end of the curve. Additionally, it will increase turbo spool and throttle response, opening the engine up and making it feel more alive. Modded and tuned 5.9 Cummins can see power gains in excess of 10whp and 20wtq depending on the mods.
One unintended added benefit is slightly better gas mileage which helps the intake pay for itself over time. Regardless of any peak power gains your Dodge will feel more alive, it’ll tow a bit more easily, accelerate a bit faster, and sound awesome.
Open intakes are the best for performance and power gains whereas closed intakes are best for people who want a quiet intake system. You can’t go wrong with any intake systems from Sinister Diesel or S&B but we also like open intakes from WCFab and closed intakes from Banks Power.
What 5.9 Cummins intake are you running or considering? Let us know if you have any questions below.