LS1 vs. LS6 Engine: What is The Difference Between Them?

LS1 vs LS6 Engine

Engines are the literal soul of any machine. They get the machine going and doing the impossible. There are quite a few engine manufacturers spread out all around the world, but few have the pedigree of General Motors.

General Motors, often known as simply GM, is an American automobile and engine manufacturer based in Detroit, Michigan.

One of the most pioneering inventions of GM has to be the small block V8 engines, commonly known as LS engines. Quite a few configurations of the LS engines are still available in the market. LS1 and LS6 are two common configurations seen in road cars.

This article will delve into details of LS1 vs LS6 and try to determine which is better.

The LS Engine Platform

LS Engine Platform

Before delving deep into the nuances and differences of LS1 and LS6 engines, it makes sense to learn what these engines essentially are. What they perform like and how they are built.

The LS engine platform was first developed by General Motors in 1997. First generation of engines had a clean sheet design with aluminum or cast-iron block material, while newer generations improved that formula. LS engines were quite revolutionary at that time, incorporating various technologies that were not common at that time.

The LS engines replaced the pentagonal cylinder head pattern with a square-four bolt design. Later models introduced three valves per cylinder design and so on. Engine blocks have gotten smaller with time without losing power. LS engines also had a cam in block tech.

All of these new features were quite a leap from older engines, so much so that even to this date, LS engines are all the rave, as they can be fitted to a variety of vehicles.

LS1 and LS6 are two of the popular configurations of this engine. At first sight, they appear very similar, although there are many differences in nearly all aspects. We will explore those differences in detail.

LS6 Vs LS1: The Differences

LS6 Vs LS1: The Differences

Before you make a pick from these two engines for your individual need, it is best to educate yourself about their differences. That will help you ultimately choose the best fit for you.


Where do we start? Let’s say, right at the start! These two engines were both part of the first generation LS engines that took over the industry by storm. The LS1 did come before the LS6.

General Motors introduced the LS1 small block engine in 1997. It had an all-aluminum body, making it stand out from all the competitors. The first cars to use this engine were the Chevrolet Corvette and the Camaro, two well-known sports cars.

LS6 engine, on the other hand, came as the iteration to the LS1. Introduced in 2002, this engine featured the same all-aluminum build as the LS1 but with some cast iron bits. LS6 had several internal structural changes from the LS1, making it more efficient and advanced overall.

The LS6 was also featured in the Corvette ZO6, and later on certain Cadillac models. It was well regarded for its power at that time and even now.

Design and Build

LS Engine Design and Build

Design is absolutely crucial not just visually but also in terms of performance. When you just glance at them, not much will appear to be different. But with a keen eye, you can spot quite a few notable differences.

These two engines are essentially built on the same concept in relatively similar platforms. LS1 and LS6 are both built out of aluminum. LS6 has some cast iron bits, but most of the construction is aluminum. As a result, they are both lightweight and rust resistant.

Nevertheless, LS6 does have some structural differences from the LS1, though. LS6 features cast windows and an intake manifold between the cylinders, which the LS1 lacks. It also uses a roller shift camshaft which the LS1 lacks.

On the other hand, the LS1 has an exhaust gas recirculation system. Later iterations miss out on this feature. Another key design difference is that the LS6 has a completely flat bottom, while the LS1 is curved. While the LS6 being newer, introduced better airflow.

Design wise, the LS6 can be considered an evolution of the LS1 formula. Many people end up modding the LS1 and what they end up with essentially is an LS6 engine. It is an iteration for sure, but a very thoughtful one.

Engine Specification

This is where the differences between the two become a little more apparent. As you may guess from the names, LS6 is a newer version of the LS1 engine. So what does that mean in terms of specifications?

Well, according to quoted figures, both the LS1 and LS6 engines have the same displacement figure at 5.7 liters. However, the LS1 produces around 345 horsepower and 405 pound feet of torque.

LS6, on the other hand, produces 385 horsepower and 385 pound foot torque. Keep in mind that both the figures are that of the engines in stock form. You can add modifications and get much higher output out of these engines.

Approximate figures suggest that both engines can output up to 400 horsepower with mods. Generally, though, the LS6 is more powerful than the LS1. LS6 engines reach up to 410 horsepower with minimal modding.

Reliability in the Real World

General Motors engines haven’t always fared the best when it comes to reliability. You should be wary before getting one of their engines. That being said, some of their engines do fare pretty well in the real world.

Comparing LS1 and LS6 in terms of reliability, there is one obvious winner, and it is the LS6. Like it works with most engine manufacturers, they introduce an engine generation and keep adding improvements over the course of its lifespan by taking feedback from users.

LS1 was undoubtedly a great engine at its time and arguably still is. But it has some barriers towards being a truly reliable engine. LS6, which came later, added better airflow. Higher compression boost and several small upgrades. These added not only performance but reliability.

Besides, the LS6 also has windows cast between the cylinder blocks. There is generally less wear and tear after similar usage in LS6 engines when compared to LS1. If reliability is anyone’s prime concern, LS6 is an easy enough pick.

Price and Availability

All other factors taken into consideration, price becomes another major one. Everyone has a price range they don’t normally like to exceed for comparable performance or features.

The LS1 is, in general, a couple of grand cheaper than the LS6. Most dealers will charge you around $4500 for an LS1 engine. On the other hand, the LS6 will cost you about $6500 dollars.

Now, the price difference is not radical, but it is certainly not small either. However, keep in mind that for the extra money, you are also getting a more reliable engine with more power and features. Thus for many, the LS6 is actually a better value, considering what they get for that price.

The Purchase Decision

After you have compared and considered all the measurable and perceivable differences, you must make the important call of actually deciding which one to get. Engines typically last years and are usually a long-term purchase. So this step is very important.

You need to first decide your priorities. Do you want to use the engine in stock form? Are you looking to modify certain things? What does your budget allow you to spend?

Well, for starters, in stock form the LS6 is much more powerful than the LS1. It has roughly 40 horsepower more, which gives a huge advantage in performance.

On the other hand, you can reach about equal amounts of power in both engines by modding them to their full potential. LS6 should still have an edge in performance, though.

Speaking of durability, LS6 is known to be more reliable. The improved airflow, ducts and design cause less wear and tear. Over extended use, that could make all the difference.

To answer this question of which one to get, our answer would be to go for LS6 if the funds allow it. LS1 is a very capable engine in its own right, and you will not be dissatisfied with it either. No matter which of these you choose, you will be getting great performance.

Related post: Difference between LQ4 and LQ9 engine.


The engine can make or break your experience of driving a car. A good engine is fast, efficient and hassle free. It provides you enough power to do what you want and do it reliably. General Motors LS engines have been on the recommended list of enthusiasts for a very long time, and for good reason.

LS1 Vs LS6 is a debate that has been ongoing for ages, with fans of both arguing about the pros and cons. We believe that both are fantastic choices worth looking at with the LS6 edging out the LS1 by a bit. We hope that this article will help you identify the best bits and pieces of each engine and make the best choice for your favorite vehicle.

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