LS1 vs. LS3: Which Engine Should I Choose?

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From time to time, the need arises for you to change the engine of your car. Vehicle owners looking to upgrade may ask the question; LS1 vs. LS3 – which of these is the superior engine?

Decision-making here can be very tough because the LS family generally shares a lot of similar traits. As such, a closer and more in-depth inspection is necessary to ensure you make the best decision.

While both are powerful and desirable engines, you can use only one. Now, we’ll be concisely highlighting the features of both engines so you know just what you’re in for.


First created in 1997, the LS1 is duly regarded as the first of the Generation III engines.

It effectively phased out the Generation II LT1 engine manufactured before it. The LS1 is made of an all-aluminum block and was initially available in only the Corvette. However, over time, it was incorporated into the Firebird and Camaro as well. It is a pure performance product. For this reason, it isn’t offered in trucks or sedans.

Another pacesetter, the LS3, is based in the Generation III family and represents part of the Generation IV engines. Its creation phased out the LS2 offered in the 2008 model Corvette vehicle.

Before going into greater detail, you should know that the LS series has a long and rich heritage. From the moment it debuted in the new 1997 model C5 Corvette, these engines remain some of the finest machines ever manufactured.

The LS1 and LS3 rank among the most efficient machines in the family. Both are powerful pushrod V-8 engines. Their compact and robust structure is built to enhance performance and improve durability.

Moving forward, here is all you need to know about these two unique members of the LS family and what they have to offer you.

LS1 vs. LS3   


Due to the fact that both machines are products of General Motors, a cursory inspection of the LS1 and LS3 reveals more similarity than disparity.

The resemblance observed includes similar center main thrust bearings, identical four-bolt per cylinder-head bolt patterns, and similar six-bolt main caps. They also have a similar deck height and stroke.

Another thing they have in common is firing order; 1-8-7-2-6-5-4-3. All the LS series boast this same firing sequence. It remains the most efficient way of firing the cylinder piston. This firing order significantly reduces any secondary imbalance and facilitates the smooth rotation of the crankshaft.

But, upon conducting a closer and more detailed inspection, the differences in the two machines start to become apparent. As the more recent of the two models, the LS3 boasts certain features that set it apart from the LS1. Clear proof of this is the larger bore and greatly improved engine head design of the former. The LS3 also has supporting modifications that increase airflow not found in the LS1.

The LS3 also features variable timing and displacement on demand. The larger bore present in the revised block of the LS3 makes it capable of increasing its displacement from 5.7 liters to 6.0 liters.

Other dissimilarities appear in the compression ratio, horsepower, and torque of the LS1 and LS3.

ls1 vs ls3
The LS3 was manufactured years after the LS1, hence the improvements in specs such as horsepower

Difference in parts

Cylinder head and bore diameter

As most automobile enthusiasts know, the cylinder head directly influences the functionality and efficiency of an engine. Even seemingly minor variations in the length, size, and port shape of this part of your engine can affect the level of performance you’re able to get out of the machine.

The LS3 engine owes its impressive base performance to the cylinder head it can accommodate thanks to its 4.065 Inches bore diameter. The 3.898 Inches bore diameter of the LS1 means that it can’t accommodate the installation of certain types of pistons. This in turn means that it can’t generate the power and clearance of the LS3. So, while the stats of the LS1 are undoubtedly great, it can’t top the LS3’s superior performance levels.

Intake and exhaust port shape

The LS1 has a Cathedral Intake Port Shape and an Oval Exhaust Port Shape. The LS3, on the other hand, has a Rectangle Intake Port Shape and a D-Port Exhaust Port Shape.

The port shape of the LS3 helps it produce low-speed power and additional flow. Also, due to the constitution of the LS3’s intake manifold flow, it can produce up to 20 horsepower more than the LS1.

Fuel injector

Lastly, the LS3 possesses a more efficient fuel injector when compared to the LS1. The high flowing injectors in the LS3 actively prevent blockage. It also influences the optimal performance of the engine. As a result, the LS3 has a higher level of efficiency. More power is generated while less fuel is consumed. Also, emission levels in the LS3 are lesser than those of the LS1.

This leads us to the next phase in our comparison.

Fuel economy

Before reading any further, please note that three factors influence the fuel economy of any engine to certain degrees. These include:

  • The way your automobile is built. That is, how parts like your cylinder head, the camshaft, and induction, among other components, are fitted into the engine.
  • The setup of your car is also essential. Factors like your choice of tires or wheels, the gear ratios, weight, and variables matter as well.
  • Finally, how you drive the car plays a role in the overall fuel efficiency of your engine.

With all these variables taken into account, the LS1 is not as fuel-efficient and economical as the LS3. The superiority of the LS3 in this department is due to upgrades like the larger fuel injector and improved modifications which promote increased airflow.

You can get no more than 15 to 16 miles per gallon from the LS1, while the LS3 can give up to 24 mpg on the highway. What it all boils down to is that the latter model is finely tuned to achieve more with less.


In many ways, it wouldn’t be inaccurate to state that the LS3 was designed to outpace its predecessors on every level. Due to its staggering ground performance of 430 horsepower from just 6.2L or 376 Cubic Inches, the LS3 isn’t only far more powerful than the LS1, but it also currently ranks as the most powerful base Corvette engine overall.

The LS3’s performance specs are also made more significant by its strengthened casting and larger bores. Because of these features, you can get the newer model to work faster and for longer than its older counterpart.

There’s a little more than a decade age gap between the LS1 and the LS3. In terms of raw power and performance, this is one of those cases where the newer engine tops older models again and again.


The LS3 is significantly more expensive than its predecessor because not many of these engines were manufactured. Another reason that it commands a higher price tag is because of the more sophisticated technology and hardware it boasts.

In light of how comparatively more available the LS1 is, you can get it for around $5, 000, at the most. On the other hand, you would need to have at least $8, 000 if you want to purchase a brand new LS3 engine.

difference between ls2 and ls3
Overall, the LS3 is supirior to the LS1, with the exception of its cost


As we can all see, the LS3 has a lot of desirable perks that make it the engine of choice for a lot of vehicle owners. However, most people end up settling for the LS1 because of how pricey the LS3 can be.

So, if you have a substantial budget, then without a doubt, the LS3 is the way to go. But, if you have a more restricted budget, then you might want to consider the LS1. Ultimately, both are great engines that get the job done and ensure your satisfaction.

Read more: LS1 vs. LS2: Which engine should I choose?

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