LS1 vs. LS2 vs. LS3: Which Engine Is Best For You?

(Last Updated On: March 23, 2023)

There’s no doubt that the LS1, LS2, and LS3 engines are terrific. However, each generation of LS engines has fantastic improvements over its predecessor. While the LS1 provides a 5.7-liter displacement, the LS2 is built with a 6-liter capacity, and the LS3 offers the highest displacement at 6.2 liters.

Total volume in all cylinders is not the only difference these engines exude. LS1 is the most popular and the easiest to find, while LS2 is arguably more difficult to find since it was produced in smaller numbers. 

Moreover, with the LS3 being the most expensive, we can say that you’ll want to think about the price when choosing which of the three engines is a suitable replacement for your vehicle’s current engine. 

This post will ultimately tell you the main differences and similarities of LS1 vs. LS2 vs. LS3 so you can make an informed choice. 

LS1 Vs. LS2 Vs. LS3 Comparison Chart 

LS1 vs LS2 vs LS3 Comparison Chart

Download the comparison chart here

What Is An LS1, LS2, And LS3 Engine?

What Is An LS1 Engine?

LS1 is the engine that GM uses in rear-wheel drive trucks, cars, and vans.

The LS1 engine was the first of GM’s Gen III small-block V8 engines, and it replaced LT1, a small-block motor in Firebirds and Camaros. Now, LS1 is the engine that GM uses in rear-wheel drive trucks, cars, and vans. 

Upon its introduction in 1997, this engine only shared lifters, bore spacings, rod bearings with its predecessors. However, it exploded in popularity since it featured 345 hp and 350 lb./ft in a compact, lightweight package. The excitement was thanks to pushing tremendous power, which was a gift for engine tuners all across the US. 

You may be asking, how many miles will a Chevy LS1 last? Well, it’s estimated that an LS1 engine can push 200,000 miles which is double that of most engines rated at 100,000 miles. 

Hence, an LS1 engine is built not only for high-performance but also for longevity. Furthermore, while LS1 enjoyed traction among tuners, drift, track and drag racers, it was only a show of what GM had in stock. The brand introduced an even more powerful engine, the LS2. 

What Is An LS2 Engine?

The LS2 is a 6.0L V8 engine with larger openings and intake openings than the LS1 engine.

In 2005, General Motors added a performance kick to the tuner’s power plant of choice with the introduction of the LS2 engine. The LS2 is a 6.0L V8 engine with larger openings and intake openings than the LS1 engine, and it boasts 400 hp and 400 lb./ft torque.

LS2 is the most adaptable LS line engine since its block can fit LS1, LS3, LS6, and LS96 cylinder heads. It has an improved block casting over the LS1 and improved torque throughout its rev range. 

As for how long it will last, you can expect it to reach more than 200,000 miles. It’s one of the most reliable and durable engines that the automotive industry has seen. 

What Is An LS3 Engine?

The LS3 engine was introduced in 2008, boasting more prowess, power, and ease of modification. Credit:

You may want to look into the LS3 engine for gearheads revering more power. This motor was introduced in 2008, boasting more prowess, power, and ease of modification. It may set you back a pretty penny, but you will enjoy 430 hp and 424 lb./ft of torque. 

This engine also offers incredible durability with the capability to last 300,000+ miles. You can expect no engine work over this period. 

Read more: Stage 1 Tune Vs. Stage 2 Tune Vs. Stage 3 Tune: Similarities And Differences

LS1 Vs. LS2 Vs. LS3: Detailed Comparison 

LS1 is a Gen III V8 engine.

Generation And Years 

As I indicated, LS1 is a Gen III V8 engine. It replaced Gen I and Gen II engine families from 2002 and 1995. LS1 was first seen in the C5 Corvette in 1997. It was used in the Corvette from 1997 to 2004, Camaro/Firebird from 1998 to 2002, and in the 2004 Pontiac GTO/Holden Monaro. 

Production of the LS1 engine for use in new GM vehicles was discontinued in 2005 upon the introduction of the LS2 engine. This engine was designed for use in sports cars and performance vehicles. It also laid the path for Gen IV small-block engines.

Although LS2 shares some similarities with the LS1 motor, it has 4.000-inch bore centers and the same cam-in-block architecture as the first small-block motor introduced in 1955. 

LS3 is still part of GM’s Gen IV family of engines. It showed up in 2008 and remained in production until 2017. Now, Chevrolet Performance produces it as a crate engine. Until 2017, LS3 was used in high-performance vehicles like the Camaro and Corvette. 


Perhaps the most significant difference between these engines is their displacement. The LS1 engine has a 5.7L (346 cu. in.) capacity, while the LS2 has a 6.0L (364.1 cu. in.) displacement. The LS3 boasts a 6.2L capacity (376 cu. in.). 

The different capacities mean that the LS3 can create more power than the LS2 and LS1 engines. 

Power Output 

LS engines are some of the most powerful in the automotive industry. While they are not all extravagant, you will find them squeezed in just about every sports car. 

For example, the Sin R1 boasts the LS3 engine since it offers 430 horsepower at 5900 RPM. Meanwhile, LS2 keeps up 400 hp at 6000 RPM, and LS1 comes in at 345 hp at 5600 RPM

If you are looking for a motor with incredible horsepower, for frequent use on freeways on-ramps, and have the high towing capacity, you will like the LS3 engine. 

However, if you want better fuel economy, LS2 is your best choice since it has midrange horsepower.

A video about the comparison between LS1 vs LS3.

Torque Output 

Looking at the torque output, LS1 was rated at 350 pound-feet of torque at 4,400 RPM when it was first introduced. Still, it saw improvements that brought its torque to 365 lb./ft of torque. LS2 provides 400 lb./ft at 4,400 RPM while the LS3 has 420 to 428 lb./ft of torque at 4,600 RPM. 

Cylinder Bore Size 

When it comes to the feel of the engine, the cylinder bore size provides the defining characteristics of the motor. LS engines have cylinder heads that are really good since they are designed specifically for the LS engines family. 

With that in mind, LS1 has a standard 3.900-inch bore. Its thin, iron cylinder liners mean it can only be bored at up to about 0.010 inches. Because of its cylinder bore size, LS1 is not compatible with the latest GM L92 cylinder heads

LS1 has 244 cfm intake and 206 cfm exhaust, which is impressive since it utilizes stock production heads. 

LS2 has a larger 4.000-inch bore, and it uses LS6 cylinder heads and’ 01-spec LS6 camshaft. Chevrolet increased the intake manifold flow on the LS2 to give you a 10whp+ gain over the LS1. On the other hand, LS3 has a 20whp+ gain over LS2. 

The bump in LS3’s displacement comes courtesy of its 4.065-inch bore. This engine is also unique because it does not have variable valve timings similar to those of other Gen III engines like the L92. It also fits a lower-profile intake manifold.

Additionally, LS3 comes with a ’01 LS6 camshaft that is slightly tweaked to include a more intake lobe lift. 

A video about LS2 vs LS3 comparison.

Piston Stroke Size 

All three engines have a 3.62-inch stroke. Despite having an identical stroke, GM manages to improve displacement in each engine by varying the cylinder bore size. That’s why LS3 has an additional 30 hp over LS2 and is more rev-happy than the other two engines. 

Compression Ratio

Although bore improvements and displacements help increase power gains in every engine, the cylinder heads impact the compression ratio significantly. LS1 has distinctive cathedral top heads while LS2 has true-flat-top cylinder heads, and LS3 has rectangular heads

The compression ratio is distinct because of the cylinder heads’ design, displacement, throttle body, and intake differences. To this end, LS1 has a compression ratio of 10.25:1, LS2 provides 10.9:1, while LS3 has the highest compression at 10.7:1. 

Block And Heads Material 

LS Engine Block. Credit:

LS1, LS2, and LS3 are all offered with a cast aluminum block and cast aluminum cylinder head. Nevertheless, LS1 has a 75mm throttle body while LS2 has a 90mm throttle body. LS2 also has a different intake manifold compared to LS1, and these include recontoured runners and a slightly greater plenum. 

LS3 boasts a more robust aluminum engine block and aluminum-alloy pistons. The high-flow cylinder heads have rectangular intake ports to support exceptional airflow. 

All the intake manifolds are composite. The exhaust manifold on the LS1 and LS2 engines are of cast iron, but LS3 has a cast nodular iron exhaust manifold. 

Fuel System

It’s essential to know the fuel system if you are an engine builder, engine tinkerer, or EFI swapper. Since the fuel system consists of fuel injectors, intake valve, piston, and combustion chamber, it’s best to discover what each motor entails.

LS1, LS2, and LS3 all utilize port fuel injection. An LS1 injector is 2.55 inches long, while the LS2 uses a 2.08-inch injector, and the LS3 comes with a 1.48-inch fuel injector. 

All three have cast aluminum pistons with 1.5mm/ 1.5mm/ 3.0mm ring package. LS3 adds piston oil squirters to cool the pistons for improved durability. 

All LS engines have knock sensors. However, the knock sensors will stop working if you change engine mounts, cam, or valve train. Hence, you will need to calibrate them again when you change any motor parts. 

Fuel Type 


The compression ratio on the LS1 engine calls for regular unleaded fuel while LS2 and LS3 perform best on premium fuel. 91 Octane is the most recommended for LS2 and LS3 engines.

For example, if you run 87 Octane on an LS2 or LS3 engine, you will lose horsepower on warm days. You’ll also notice that the engine tends to ping like an old vehicle. You may get away with using 87 Octane in the cold winter months, but you’ll get more out of your engine when you use premium fuel. 

This is because LS1, LS2, and LS3 engines are designed to take advantage of the higher Octane. Although General Motors recommends using premium fuel, it also notes that it’s not necessary. 

Oil System 


The oiling system in the LS1 utilizes the conventional “wet sump” design. The oil pickup is rear-mounted in the oil pan, and its oil filter is next to the rear of the engine while the oil pump is on the block’s front and driven directly off the crankshaft. This system reduces drag on the valve train and minimizes pumping and deflection losses. 

LS2 uses a slightly tweaked Gen III oil system. It adds an active oil management system; hence its oil galleries have been redesigned to maintain correct oil pressure as various cylinders are activated and deactivated during use. 

Finally, LS3 utilizes a dry-sump design. The engine has two oil pumps and a separate oil reservoir. It also includes a pressure relief valve that regulates the negative pressure in the engine. Thus, the internal seals are not inverted. 


LS1, LS2, and LS3 engines have some swappable parts. They all have identical (four-per-cylinder) head bolt patterns, so all heads are compatible with each other. However, you can only use LS3 heads in a 4.000-inch or larger bore.

You may require some grinding on older design LS1 engines to clear the offset intake rocker. LS engines also have a different intake runner shape, requiring a different intake manifold.

However, even though you get a factory intake with a 90-mm throttle body, injectors, and fuel rails, the injectors and fuel rails are not compatible with LS1’s computer and wiring harness. When making replacements, you will need to purchase injector plug adapters, a cable bracket, and a 90-mm cable throttle body for an LS1 engine. 



LS1 is still the most popular of LS engines since it changed the game in the automotive industry. Although it was replaced with the LS2, it is still easy to find and is the cheapest of the three engines. You can expect to spend $1,500 to $2,500 on an LS1 motor.

As the horsepower creeps up to 400 hp, you are no longer in the budget range. To this end, an LS2 will set you back $2,500 to $4,500

Now, thanks to its impressive horsepower and torque, LS3 will have you spending $4,200 to $6,200 for a used motor and $7200 to 9,200 if you buy a new one from General Motors. 


LS engines are some of the most reliable engine families since they started production over 20 years ago. One of the main reasons to choose an LS1, LS2, or LS3 is availability.

Thanks to their popularity, GM continues to produce these engines for enthusiasts who want to adopt them for swaps.

You’ll also notice that LS1, LS2, and LS3 are incredibly stout capable of impressive performance numbers even without modifications. In addition, you can use an LS1, LS2, or LS3 in sports cars and even trucks, creating a buyers’ market in US junkyards. 

Lastly, you can find ready aftermarket support for any LS engine on great platforms.

A video about LS engine overview.

Common Problems 

With all their advantages, these LS engines are not without their problems. The most notable one is the 1997 to 1998 LS1 blocks. Owing to their particularly thin cylinder liners, they can only tolerate a 0.005-inch hone during a rebuild. Furthermore, 1997 to 1998 LS1 blocks tend to spot if left bare on a shop floor. 


Another problem with all three engines is that some may have bad piston ring seals, which may increase the engine’s blow. 

Additionally, these engines lack priority main oiling. It means that the oil does not necessarily go to the mains first and then to the heads. As such, the engine can experience the effects of oil pressure drops at high RPM. 

Maintenance can also be a problem since the camshaft is difficult to reach due to the pushrod design. It necessitates primarily removing the radiator or the engine when replacing the camshaft. 

Lastly, the skirted block design limits the engine’s ability to reduce windage using traditional methods. Since the power pouches and crank scrapers are entirely removed, the effectiveness of windage trays is diminished. 


To summarize, LS1, LS2, and LS3 engines are similar in a few features, but they are not equal. As you’ve seen, the displacement, bore diameter, head bolts, and cylinder length define these engines. 

LS2 is an upgrade of the LS1, while LS3 is an upgrade of the LS2. Therefore, if you are looking for the most powerful engine among the three, LS3 is my recommended choice. 

So, are you ready to choose between LS1, LS2, and LS3? You can do so with confidence.


  • Randy Worner

    My name is Randy Worner and I am the founder of I have been working on cars and trucks for almost 45 years. For the last 36 years I have taught Automotive / Diesel Technology classes for UTI, Snap On Tools, Chrysler, Pepboys, Lone Star College, NAPA and TBC Corporation.I also own a technical writing company known as Supreme Technical Services. It is ASE Gold Seal certified and Blue Seal Certified Author of auto/truck repair information.

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