LS7 vs LS9 Engine Head Series

LS7 vs LS9 Engine Head Series

General Motors manufactures superpowered LS engines in a wide range. LS7 and LS9 are the two most advanced versions of the LS engine series. Though both are well recognized, this article is about the sharp difference between LS7 and LS9.

What are LS7 and LS9?

LS7 and LS9 are the two latest versions of the LS engine series. LS7 is a generation IV engine incorporated in the Corvette. The LS9 engine is also part of the generation IV family made for Corvette.

LS9 vs LS7 Table

Some notable differences between LS7 & and LS9 engines are shown below:

Compression Ratio: 11:1

Compression Ratio: 9.1:1

Horsepower rating: 505

Horsepower rating: 638

Torque rating: 470-481 ft./lbs

Torque rating: 470-481 ft./lbs

Displacement: 7L

Displacement: 6.2L

Piston style: Flat top, with valve reliefs

Piston style: Flat top, with valve reliefs

Piston volume: +7cc

Piston volume: +15cc

Exhaust runner volume: 86cc

Exhaust runner volume: 89cc

Valve angle: 12 Degrees

Valve angle: 12 Degrees

Throttle body: 90mm, 4-Bolt, Silver   Blade

Throttle body: 87mm

Fuel injector flow: 41.74 lbs/hr

Fuel injector flow: 59 lbs/hr

Induction: Natural aspirate (Modifiable)

Induction: Natural aspirate (modifiable)

Why Compare?

As LS7 and LS9 are supercharged generation IV engines, it’s hard to understand the difference. Especially for large buyers, it becomes challenging to choose one of them. Moreover, when someone decides to buy a sports car, they get confused about the car engine. As the engine is the main part of a car, people always give maximum attention to this. That’s why it becomes important to know the difference between various engine versions.

LS engine series provides an extensive range of choices. Thus, the confusion gets even worse. The main object of this article is to help people make their choice more accessible by providing a wide idea about two famous and supercharged LS engine versions (LS7 & LS9).

Equipped Cars:

LS7 engines are mainly designed for Corvette/Camaro models of Chevrolet cars. The most famous equipped vehicle models are- Chevrolet Corvette Z06 and Camaro Z/28. LS9 is used in many cars along with Chevrolet. Some are Chevrolet Corvette ZR1, HSV GTSR W1, and Equus Bass 770.


Acceleration is the rate of increase of velocity in unit time. LS9 shows more acceleration than LS7 for its high horsepower and torque rating. The LS9 produces propelling the ZR1 to ¼ mile times of 11.3 seconds. Additionally, the LS9-equipped ZR1 posts 0-60 MPH times of only 3.4 seconds and 0-100 MPH times of 7 seconds.

On the other side, it can achieve 0-60 acceleration in 3.7 seconds, quarter-mile times of 11.7 seconds at 127 mph, and a top speed of 198 mph.


RPM stands for revolution per minute. It indicates the speed of the operating system of an engine. LS7 and LS9 show little difference in rpm. Though the rpm value depends on other factors, LS7 shows a 7000 maximum rpm. On the other hand, the rpm of LS9 is 6600.

RPM is a good indicator of speed but can’t describe the generated power of an engine. LS7 has the largest displacement cylinder in the LS engine series, contributing to its high rpm value.

Fuel Injector flow:

Fuel injector flow indicates the maximum amount of fuel flow in an inter-combustion engine for burning in a given amount of time at a given pressure. The more fuel is burnt in the engine, and the more power is generated.

The above chart shows LS9 has a higher fuel injector flow than LS7. That means LS9 generates more power than LS7 by burning more fuel. That’s a reason behind the low fuel efficiency and highest power generation capacity of LS9 engines.

Fuel efficiency:

LS7 and LS9 show significant differences in fuel efficiency. In this specification, LS7 stays a step forward than LS9. Mileage is a car feature that depends on the engine’s fuel efficiency. The more fuel efficiency of the engine, the more the car gets mileage.

It gives an average mileage of 30-31 MPG. On the other hand, LS9 fuel efficiency is lower than LS7, which is 22 MPG, due to its high fuel injector rate. But LS9 possesses a lot more power for its built-in supercharging capabilities.


Nothing is more important than pocket management! Whatever the configurations are, everything depends on affordability. So, the cost is one of the things that should be considered first.

Both LS7 and LS9 are costly, but LS9 is more expensive than LS7. Its cost has been reduced by thousands. Its formal price was almost 17000$, which is now 15000$. On the contrary, LS9 cost 21000$, a lot more than LS7.

Which one should you go for?

Well, it depends. LS7 and LS9 both are high functioned the latest technology of general motors. LS9 lacks fuel efficiency but has more horsepower rating, torque rating, maximum speed capability, and many other eye catchy features. Moreover, LS9 is the most powerful engine in the LS series.

So, it has its legacy before finishing the article, check this ls1 vs ls6 comparison too. On the contrary, LS7 is more fuel efficient and operating speed (rpm) than LS9. Another important fact is the affordable cost that makes LS7 highly demandable.

Frequently Asked Questions (FAQ)

LS3 is a newer engine that was introduced in the sixth generation of Chevrolet Silverado and GMC Sierra trucks. It is a more powerful and efficient engine than the LS9, making it the better choice for most truck drivers. However, if you need the extra power and towing capacity that the LS9 offers, then it may be the better option for you.

Yes, the LS9 engine has forged internals. This makes it incredibly strong and durable, able to handle high levels of power and stress. As a result, it’s a popular choice for performance applications.

How much horsepower can an LS7 handle?
An LS7 engine can handle up to 505 horsepower. This makes it a great choice for high-performance applications. It is also very reliable and can withstand a lot of wear and tear.

The LS7 is a more powerful engine than the LS3, but it is also more expensive. If you are looking for a powerful engine for your car, the LS7 is a great choice. However, if you are on a budget, the LS3 may be a better option.



As we can see, both the LS7 and LS9 engines have their own pros and cons. It really depends on what you prioritize when it comes to choosing between the two. If you’re looking for an engine with more power and performance, then the LS9 is the way to go. However, if you’re more concerned about fuel efficiency and cost, then the LS7 would be a better option. Ultimately, it’s up to you to decide which engine is the right fit for your needs.

LS9 Engine

LS7 Engine

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