LMM Vs LML- Which One Is Better?

What is the difference between LML and LMM? LML is the advanced and more sophisticated version of the LMM. Apart from that, there are a few significant differences among them.

So, if you are considering LMM vs LML, which one should you pick? Well, it is a matter of discussion based on what best fits your needs.

However, we are comparing them in terms of- Mileage, Emission Equipment, Build-Quality, Engine Power, Towing capacity, and Price. Go through the discussion below to get all the relevant information and make the right decision.

LMM Vs LML: Key Comparison Between LMM And LML

Key FactorsLMMLML
Mileage300,000 miles400,000 miles
Engine Power in HP (Horse Power)365HP397HP
Build-QualityCast Iron, Cast Aluminum, Forged SteelCast Iron Block, Aluminum, Forged Steel, Nitride Hardened
Towing Capacity (Up to)16,700 lbs23,200 lbs

Build Quality Differences Between LMM And LML

When you compare the Chevy LMM vs LML, you can notice a significant difference between their built quality.

The Duramax LMM has cast-iron block material and a cast aluminum cylinder head. The block engine material for the LML engine material is cast gray iron block, and the cylinder head material is cast aluminum alloy.

Both have Forged Steel connecting rods. The LML has a Forged Steel and Nitride Hardened crankshaft, while the LMM has only a Forged Steel crankshaft. The intake manifold of the LML is cast aluminum.

Emissions Equipment in LMM and LML

Between the years 2007.5 to 2010, the 6.6L LMM Duramax came with a whole new emission system. This engine was equipped with Diesel Particulate Filter (DPF), Diesel Oxidation Catalyst, and Exhaust Gas Recirculation. Chevrolet Silverado HD and GM Sierra HD trucks have these emission systems installed in their diesel engines. The DPF resulted in a better emission rating.

However, it reduces the fuel performance significantly. Due to the post-injection regen method, this new emission device has reduced the ultimate engine performance. Nevertheless, it is still a reliable diesel engine for trucks.

In the later years between 2011–2016, General Motors introduced Selective Catalyst Reduction or SCR, which is also known as the 9th injector in the Duramax LML.

Also, this system was installed along with the Exhaust Gas Recirculation (EGR) and EGR Cooler in the DPF system to maintain a stricter emissions standard, reducing to 63% emission. As a result, there was a reduced soot deposit.

LMM And LML MPG/Mileage Comparison

The mileage for any 2.8L Duramax diesel engine is about 5 years/60,000-mile. And for the 6.6L Duramax diesel LMM vs LML Turbo engine, the mileage is 5-year/100,000 miles. So, there is really no difference between the LMM and LML versions of the Duramax diesel engine.

However, The LML has better mileage than the LMM when compared to the overall service time or miles coverage. The Duramax 6.6L LML engine covers up to 400,000 miles, while the 6.6L LMM only covers 300,000 miles, quite a big difference, as you can see.

LMM And LML Have Dissimilarities In Their Engine Power

When you compare the LMM and LML in terms of engine power, you may not find a big difference. There is only a little gap between these two engine variations. And it can barely affect your buying decision of the engines.

The LMM has 365HP, whereas LML provides 397HP. However, you may notice a significant difference between them while riding on rough, smaller trails. You may find the LML riding smoother. Otherwise, it is no big deal.

Towing Capacity In LMM And LML

Towing capacity depends on a few things- cab configuration, LMM vs LML years of production, etc. If you compare the towing capacity of the engines, Duramax LML would be a frontier.

The 6.6L LMM has a maximum towing capacity of 13,000 lbs with a single rear-wheel truck. But with a dual rear wheel truck, the Duramax LMM has a higher towing capacity. In that case, the hauling capacity increases to 16,700 lbs when towing a fifth wheel.

The maximum conventional tow capacity of the Duramax LML varies on the year made and whether it is being used in a Dually or in an SRW (single rear wheel).

Also Read: LB7 Vs LBZ- The Complete Comparison Guide!

However, the standard towing capacity starts from 13,000 lbs on an SRW, and it goes up to 20,000 lbs on a Dually. The maximum 5th wheel tow can be up to 17,500 lbs for SRW vehicles. But for Duallies, it is 23,200 lbs.

The minimum highest payload is 3,275 lbs in the year 2015-16. The payload capacity rose up to 5,740 lbs in the year 2011-14. Also, the Gross Vehicle Weight Rating or GVWR for a Duramax LML is 13,025 lbs max and 10,000 lbs at its lowest. GVWR measures the total weight of the truck, including the passengers and the load.

LMM And LML Price Differences

When you compare the price of Duramax LML V8 with the LMM V6, you will notice a big difference between them. On a typical note, a V6 engine costs about $5,500, whereas a V8 engine will cost you $7,000. So, you can clearly see how the engine price rises as it gets advanced.

Generally, the replacement cost for your car engine is about $1000 in your local engine repairing shop. But it can vary a little and might cost you up to $4000. However, an entire engine replacement is super costly.

The price also varies a lot on the rebuilder. With a professional replacement, you will have to spend more. It can charge you up to $25,000, starting from $15,000. It is because the process includes the replacement cost along with the engine price.

Apart from that, there is a noticeable difference in the regeneration intervals of both LMM and LML. In a steady driving module, an LML engine regeneration occurs every 600 to 700 miles, less frequently than an LMM. On the contrary, in LMM, the regeneration may occur in every 300 to 400 miles of driving.

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Frequently Asked Questions (FAQs)

What’s the Difference Between LMM and LML?

The main difference between LMM and LML engine types is in their exhaust system. LML has a better and more effective emission system compared to LMM. However, it affects the mileage of the vehicle badly.

What Year Was the LMM Duramax?

Chevrolet Silverado HD and GM Sierra HD trucks have the LMM Duramax V6 model that is also suitable for the model years 2007 to 2010. It started being produced in the middle of 2007 and was in production till the beginning of 2011. This V6 model is better equipped with a 6-speed Allison transmission.

What Year Did LML Stop?

The V8 LML engine was in production from 2011 to 2016. This 6.6L Turbo-Diesel engine was an upgraded version of the previous V6 model. It is not clear the exact reason behind its discontinuation, but one probable reason is the complexity in the fluid pump due to contamination.

Is the LML Reliable?

LML is quite a reliable engine. This V8 engine model can provide service up to 400,000 miles when you take good care of it. It is an advanced model of the LMM series with some drastic changes in its emission system. The DEF system installation has made it a safer engine for the environment. However, some owners prefer to remove it illegally to attain some extra mileage. But if the fluid pump fails, the engine can stop working as early as 30,000 miles.

Is the LMM Duramax a Good Engine?

LMM Duramax is quite a durable engine. Even though it has a Diesel Particulate Filter that is thought to be a performance reducer, it may still last up to 300,000 miles without facing any major issues. However, one should maintain it pretty well to get the best service. Otherwise, it is a reliable engine, you can say.


So, when comparing LML vs LMM, both have their positives and negatives. One really can not replace another. If you are tight on budget, LMM is a better pick for you. But,  if you are looking for better torque towing capacity, the Duramax LML would be a better pick.

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Ronald Berit

Our chief editor, working 24/7 to ensure the precise and only quality data regarding different trucks.He is mastered with the ins and outs of cargo to off-road trucks of Dodge, Ford, Chevy, Toyota, GMC and more. This truck geek graduatedwitha Bachelor of automobile engineeringdegree and practiced through his own automotive parts repair center.

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