Home FAQ

How do I know if I have a LS or LT engine?

Determining whether your vehicle has an LS or LT engine can be important for maintenance, upgrades, and understanding its capabilities. The LS and LT engine designations refer to different General Motors engine families, each with their own unique characteristics. Here's how you can identify which type of engine your vehicle has.

What are LS and LT Engines?

The LS engine family is a series of V8 engines produced by General Motors, first introduced in 1997. LS engines are known for their power, reliability, and widespread aftermarket support. The LT engine family is a more recent series of V8 engines, introduced in 2013, that share some similarities with the LS but have their own distinct features.

How to Identify LS vs. LT Engines

There are a few key differences between LS and LT engines that can help you identify which one is in your vehicle:

Engine Block: LS engines have a taller engine block, while LT engines have a shorter, more compact block.

Intake Manifold: LS engines have a traditional intake manifold design, while LT engines use a more modern, integrated design.

Fuel System: LS engines use a traditional port fuel injection system, while LT engines use a direct injection system.

Cylinder Heads: LS engines have rectangular-port cylinder heads, while LT engines have cathedral-port cylinder heads.

Engine Codes: LS engines typically have a 4-digit engine code (e.g., LS3, LS7), while LT engines have a 3-digit engine code (e.g., LT1, LT4).

If you're still unsure, you can also check the engine code stamped on the engine block or the vehicle's identification number (VIN) to determine the specific engine model.

Conclusion
Identifying whether your vehicle has an LS or LT engine is important for understanding its capabilities, maintenance requirements, and potential for upgrades. By looking at the engine block, intake manifold, fuel system, cylinder heads, and engine codes, you can easily determine which type of engine you have and make informed decisions about your vehicle's performance and modifications.

How do I know if I have a LT or LS Engine?

When you open the hood, there is a label attached to the front of your car on the metal crossbar in front of/ above your radiator. This label will tell you what engine your car has.

How do I tell what engine I have?

You can find your engine type by checking the Vehicle Identification Number (VIN), which is on a sticker inside the driver's side door, on the dashboard, or in your owner's manual. Use the VIN to look up the car's specs online, as the eighth character often indicates the engine size and type. Additionally, some cars have the engine size stamped directly on the engine block or on a sticker under the hood.

This video explains how to decode your car's VIN to find engine information: 59sSimple Mechanic AdviceYouTube · Jan 3, 2025
1. Use the VIN

Find the VIN: Look for the 17-digit VIN on the driver's side of the dashboard visible through the windshield, on the driver's side doorjamb, or in your owner's manual and on your insurance card.
Decode the VIN: Enter the VIN into an online VIN decoder, such as the one on the National Highway Traffic Safety Administration (NHTSA) website. The eighth character of the VIN will contain information about your engine.

This video shows how to find the engine size from under the hood using a sticker: 33sMegaMilesBenYouTube · Nov 15, 2021
2. Check the engine compartment

Look for a sticker: Some cars have a sticker on the engine itself, often on the timing cover, that displays the engine code and size.
Look for stamps: The engine block may have a stamp indicating its size, such as "3.3L" or an engine series code like "RB30".

3. Consult your documentation

Owner's manual: Your car's owner's manual contains detailed information on the vehicle's specifications, including the engine type.
Vehicle title and registration: The VIN and other vehicle details are also listed on the title and registration documents.

You can also watch this video to learn how to find the VIN on your car's dashboard: 54sMr. B's Auto shopYouTube · Aug 18, 2020

How do I identify my LS Engine?

You can identify an LS engine by checking the 8th digit of the Vehicle Identification Number (VIN), using casting numbers stamped on the engine block or cylinder heads, or by a visual inspection of the timing cover and intake manifold. Each method can provide specific details like the engine's model, displacement, or generation.
Methods for identifying your LS engine
This video demonstrates how to identify an LS engine visually and by checking the VIN: 59sCoverman66YouTube · Mar 7, 2022
1. Use the VIN

Locate the VIN on the vehicle's dashboard or door jamb.
Find the 8th digit. This letter or number corresponds to a specific engine RPO code.
Look up the 8th digit in a guide to determine the engine model and specifications.

2. Find and decipher casting numbers

Look for a casting number on the engine block or cylinder head, typically on the passenger side near the rear.
The casting number is a long string of digits. You can search for these numbers online to find the exact engine type, notes JustAnswer.
For example, casting number 12621766 often indicates an LS3 engine, while 12623968 often corresponds to an LS7, says Snake Eater Performance.

This video shows how to find and use casting numbers to identify an LS engine: 57sCoverman66YouTube · Jan 13, 2020
3. Perform a visual inspection

Timing Cover: Compare a "plain" timing cover to a "sensor" timing cover. A plain cover often indicates an LS1, LS6, or older truck engines (like the LR4, LM7), while a sensor cover is common on newer engines (LS2, LS3, L76).
Intake Manifold: Check the intake manifold. Car engines typically have a specific intake manifold, while truck engines have a different style.
Engine Block: Look for the displacement cast into the front of the block. You might see "6.0L" or "5.3L," for example, notes Reddit.
Cylinder Heads: Some engines have distinctive cylinder heads. For example, LS7 heads have a unique intake bolt pattern and an increased rocker ratio.
Knock Sensor: Note the location of the knock sensor. If it's in the valley, it's likely a Gen 3 engine; if it's on the side of the block, it's likely a Gen 4.
Cam Sensor: Check the cam sensor location. It's at the back of the block for Gen 3 engines but in the timing cover for Gen 4 engines.

You can watch this video to learn how to visually identify LS engine generations: 49sSummit RacingYouTube · Jun 17, 2014

Is a 5.3 a LS or LT?

The 4.8L and the 5.3L are smaller truck versions of the LS1 and were designed to replace the 305 and the 350 in trucks. The 4.8L and 5.3L engines share the same Gen III LS-series engine block and heads (upper end) and therefore, most parts interchange freely between these engines and other variants in the LS family.

Kevin Bennett

Company Owner

Kevin Bennet is the founder and owner of Kevin's Autos, a leading automotive service provider in Australia. With a deep commitment to customer satisfaction and years of industry expertise, Kevin uses his blog to answer the most common questions posed by his customers. From maintenance tips to troubleshooting advice, Kevin's articles are designed to empower drivers with the knowledge they need to keep their vehicles running smoothly and safely.