The name “Duramax” can refer to any of the choices of turbo-diesel engines used by General Motors in several of their vehicle models throughout the years.
While Duramax engines are predominantly V8 ones, there are also some that are inline-4s (I4) and even one inline-6 (I6).
But regardless of the size of the engine, all of them have one thing in common, and that is they obviously need oil to run smoothly.
The question is, how much oil do you put in a Duramax engine?
To answer that and many other related questions that you may have, we have listed each Duramax engine’s oil capacity as well as other essential details below.
What is the oil capacity of a Duramax engine?
All 6.6-liter Duramax V8 engines have an oil capacity of 9.2 quarts (8.7 liters), while the 3-liter Duramax I6 engine has 6.4 quarts (6.1 liters).
The 2.8-liter Duramax I-4 engines have an oil capacity of 5.5 quarts (5.2 liters), while the 2.5-liter Duramax I-4 engine has 4.4 quarts (4.2 liters).
It’s important to note that the values that we have stated above are when the oil filter is not yet included.
When you factor in a new oil filter, that’s going to significantly change both the oil capacity and oil weight for all of the engines.
To properly introduce all of the Duramax engines, we have also included each of their engine codes, displacements, cylinder arrangements, and production years in separate columns.
Their oil capacity will be in quarts (qt), and their oil weight will otherwise be in pounds (lb).
As a general rule, all of the engines with the same displacements and cylinder arrangements will also share the same oil capacity and oil weight.
You can also see that as the size of the engine goes up, so does the maximum oil capacity and oil weight.
When it comes to oil weight, all of the 6.6-liter Duramax V8 engines are the heaviest to tip the scale at 17.3 to 18.8 lbs without and with the oil filter, respectively.
The 3.0-liter LM2 engine is the only Duramax inline-6 engine and is the middleweight of the bunch with an oil weight of 12.11 to 13.2 lbs.
The two 2.8-liter engines, namely the XLD28 and LWN, both have an oil weight of 10.38 to 11.3 lbs, depending on whether you include the oil filter or not.
The 2.5-liter XLD2 engine is the smallest Duramax engine that’s currently in production to this day. Its oil weighs 10.38 lbs without the filter and 11.3 lbs when it’s included.
The Amount of Oil Pressure in a Duramax Engine
Moving on to another important oil-related aspect, the Duramax is going to have its own oil pressure just like any other internal combustion engine.
It’s important to know what amount of oil pressure is considered normal for your specific Duramax engine, as this is one of the ways to tell if your engine is running smoothly.
We have provided a table below with all of the engines that were listed earlier, along with their oil pressures (in pounds per square inch) both at idle and at 1800 RPM (revolutions per minute).
As you can see above, there is a big difference in oil pressure at idle and at 1800 RPM for all Duramax engines, which is the general rule when it comes to oil pressure anyway.
As the engine rotates faster at higher RPMs, oil pressure also rises until the oil pump’s relief valve open’s up and lets the excess pressure out.
We can see that the oil pressure is identical for all engines of the same displacement, regardless of the engine code or generation.
All of the 6.6-liter V8 engines get 14 psi of oil pressure at idle and raise up to 42 psi at 1800 RPM.
The 3.0-liter I6 engine, surprisingly, has the highest oil pressure at idle among all of the Duramax engines at 14 psi.
However, it ties both the 2.8 and 2.5-liter I4 engines at 40 psi of oil pressure at 1800 RPM.
Other than that, all of the I4 engines only have 13 psi of oil pressure at idle.
How and When to Change a Duramax Engine’s Oil
Now that you’ve got the oil capacity, oil weight, and oil pressure of the Duramax engine down, we’ll be talking about actually changing the oil.
While there are tons of tutorial videos out there that may have some slight differences between their oil change procedure, they still have a lot of steps in common to keep in mind.
The list of steps will only serve as a general guide and is not a substitute for an actual professional oil change for your specific vehicle.
General Steps for a Standard Oil Change
- For vehicles that don’t have much clearance to work underneath them, you need to lift them up with a hydraulic jack and jack stands first.
- Remove your vehicle’s undertray (if it has one), place an oil drain pan directly underneath the drain plug, and remove the plug slowly to allow the oil to drain.
- Unscrew the oil filter (near the drain plug) slightly until excess oil comes out on top and drips into your pan. Wait until it subsides before removing the filter completely.
- Make sure that the old oil filter gasket (a rubber O-ring) did not get left behind before installing a new oil filter.
- Put a small amount of oil around the new oil filter’s gasket with your finger.
- Install the new filter and screw the drain plug back snug. You can refer to their manufacturer’s guide for the proper torque spec to avoid overtightening them.
- Reinstall the undertray and lower the vehicle back to the ground. Open the vehicle’s hood and unscrew the oil cap (located near or on top of your engine’s valve cover).
- Using a funnel, pour the new oil into the engine until you reach the indicated capacity (refer to the first table above for each Duramax engine).
- Screw the cap back on and let the oil settle for a few minutes. Pull out the dipstick (usually yellow or orange), wipe it with a cloth, reinsert it, and check the oil level.
- After confirming that the oil level lines up with the full marking on the dipstick, start the vehicle and let it warm up. Be sure to check for any leaks under the vehicle.
Oil Change Interval for the Duramax Engine
When it comes to the frequency of the oil change, it can vary depending on the specific type of Duramax engine.
But there is a general interval range for all of these Duramax engines, which would be every 5,000 to 10,000 miles (8,000 to 16,000km) driven or at least once a year, whichever comes first.
Since this is a sizable range to work with, we recommend checking your own Duramax-powered vehicle’s manual in order to get a more specific interval.
It’s common to change the oil filter every time you change the oil itself. But for the Duramax engine, specifically, you need to have its oil filter changed every 7,500 miles or 6 months.
Don’t forget about the Duramax engine’s fuel filter as well, as this needs a change every 15,000 miles driven or annually, whichever comes first.
What’s the best oil to use for a Duramax engine?
The type of oil that’s recommended for a Duramax engine will slightly vary depending on the current climate of your region.
Generally, you have the option of a 15W-40 or a 5W-40 oil for your Duramax engine.
15W-40 oil is the more common choice, as this is well-suited for regions with average to hotter climates.
5W-40 oil, on the other hand, is better suited for Duramax owners that live in colder regions or at least whenever temperatures dip low enough during the winter.
Though both will have the same initial viscosity at room temperature, 5W-40 oil will be thinner or less viscous in colder conditions, thus making it more effective in lubricating the engine.
Vehicle Models That Use a Duramax Engine
The Duramax engine has been used to power a lot of General Motors (GM) vehicle models throughout the years.
It first started as a joint venture between GM and Isuzu in 1998. Over two million Duramax engines have been produced since then.
LB7 (2001 to 2004)
The first Duramax engine was introduced in 2000, and it was assigned the “LB7” engine code. This was the first of seven 6.6-liter V8 Duramax diesel engines ever produced.
It was initially used in several Chevrolet and GMC trucks like the Silverado HD, Kodiak/Topkick, and Sierra HD during its time.
LLY (2004 to 2005)
The second 6.6-liter Duramax V8 engine was called the “LLY”, and it was only in production for two years starting in 2004.
This specific engine was also used in the Chevy Silverado and GMC Sierra HD back then. It was additionally used to power the Hummer H1 Alpha in 2006.
LBZ (2006 to 2007)
The LBZ was the third of the Duramax V8 engines, and it boasted better engine internals, fuel injection, and emissions control than the first two engines.
This engine was used in a ton of Chevrolet and GMC vehicles as well.
These were the Chevrolet Silverado HD, Chevrolet Express, Chevrolet Kodiak, GMC Sierra HD, GMC Topkick, and GMC Savana.
LMM (2007 to 2010)
The 6.6-liter “LMM” V8 engine was introduced halfway through 2007, and it was fitted in all of the previously-mentioned models for the LBZ but for the 2007 to 2010 production years.
It was the first of the V8 engines to use a diesel particulate filter as well as even more improvements in emissions without sacrificing too much power.
LML/LGH (2010 to 2017)
The LML and LGH V8 engines were made within almost the same set of production years, which is why we’ve lumped them together for this entry.
The LML was the more powerful of the two, boasting 397hp while keeping even lesser engine emissions than the LMM. It was fitted in both the Silverado HD and Sierra HD of that time.
The LGH, on the other hand, only had 335hp and was used instead for the Chevrolet Express and GMC Savana vans.
L5P (2017 to Present/2022)
The L5P is the newest of the Duramax V8 engines and is still currently in production for the 2022 model year.
This 445-horsepower engine is used in the current-generation Chevrolet Silverado HD and GMC Sierra HD.
LM2 (2019 to Present/2022)
The 3.0-liter turbocharged “LM2” engine is the first and only inline-6 (I6) Duramax engine that’s currently in production.
Only debuting last 2019, the LM2 has since found its home at the engine bays of several Chevy models like the Silverado 1500, Tahoe, and Suburban.
It’s also used as the powerplant for the GMC Sierra 1500, GMC Yukon/Yukon XL, and Cadillac Escalade/Escalade ESV.
XLD28 (2012 to Present/2022)
The XLD28 engine is one of two 2.8-liter inline-4 (I4) Duramax engines ever produced and is still currently in production.
It’s actually based on the Italian engine manufacturer VM Motori’s A428 engine, as GM owned part of the company’s shares and has earned rights to the engine even after selling the shares.
It’s currently used by GM to power several of their mid-size diesel-powered vehicles, namely the Chevrolet Colorado, Chevrolet Trailblazer, and even their Holden counterparts abroad.
LWN (2014 to Present/2022)
Two years after the XLD28’s debut, another 2.8-liter engine called the “LWN” was introduced and dialed in specifically for the North American market only.
Although this specific engine was already being produced in GM’s Rayong plant in Thailand since 2011, it was only used in models such as the USDM Chevy Colorado starting in 2016.
The LWN engine is also currently fitted in other GM vehicles like the GMC Canyon, Chevrolet Express, and GMC Savana.
XLD25 (2011 to Present/2022)
The XLD25 is another inline-4 (I4) turbo-diesel engine manufactured by GM since 2011. But unlike the previous two I4 engines, this one only had a displacement of 2.5 liters.
It’s the smallest of all the Duramax engines ever produced, earning it the nickname “Mini Duramax”.
GM has also been using this 163-horsepower powerplant as another option for the Chevrolet and Holden Colorados, Chevrolet Trailblazer, and even the Isuzu KB model.
Will there be a new Duramax engine for 2023?
There have been several reports and articles regarding GM’s production of a new Duramax engine, and one is actually already set to be used in some models in 2023.
GM has called it the “LZ0”, and it’s going to be another 3.0-liter turbo-diesel inline-6 (I6) engine just like the LM2.
According to GM, the LZ0 will have a bumped-up power figure of 305hp compared to the LM2’s 277hp.
While we have no news of its specific oil capacity and other related measurements just yet, it will be the second Duramax I6 engine to be made by GM ever since the LM2’s debut in 2019.
Thus, it’s not entirely impossible for its oil capacity to be similar to the LM2’s. But for now, we can only speculate as more of its specifications get revealed over time.
