Chevy Engine Code by VIN: 8th Digit Chart for Silverado

The 8th character of the VIN is the engine code on the gas and diesel Chevrolet and GMC cars, SUVs and light trucks in this guide. On a 2020 Silverado 1500, for example, a D in that position means the 5.3L V8 (GM code L84), an L means the 6.2L V8 (L87) and a T means the 3.0L Duramax diesel (LM2).

GM says this in its own paperwork. The Technical Data chapter of the 2020 Silverado owner's manual states that "the eighth character in the VIN is the engine code" and prints a table of those codes.

The other codes in this guide come from NHTSA's vPIC database, which holds GM's VIN filings. We queried it in October 2026, and the engine mappings below are what vPIC returns. For a single vehicle, the quickest route is our Chevy VIN decoder, which returns the engine, plant and recalls together.

Which digit of a Chevy VIN is the engine?

Count to the 8th character. In a 2020 Silverado VIN that starts 1GCUYDED, the 8th character is D, the 5.3L V8.

Federal rules in 49 CFR Part 565 require the manufacturer to describe the engine type in this part of the VIN. Our guide on how to read a VIN walks through every position.

VIN engine code vs RPO engine code

GM uses two kinds of engine code, and it helps to know both.

• VIN engine code: one character, the 8th in the VIN on the models in this guide. It is short, so GM reuses letters from one generation to the next.
• RPO code: a three-character Regular Production Option code that names the exact engine, such as L84, L87, L8T or L5P. Parts catalogs, forums and service departments use it all the time.

When you decode a GM VIN, vPIC usually returns the RPO code in its engine model field. That is why the tables below list both. The RPO code tells you more than the displacement alone. For example, a 2020 Silverado can have two different 5.3L V8s: F (L82) and D (L84). GM's owner's manual lists them as separate engines with separate cooling system capacities.

Silverado 1500 engine codes by year

Silverado codes changed with each generation, so check the model year (10th character) first. Our VIN year chart decodes it.

2008 Silverado 1500

vPIC also lists other 5.3L variants for this generation, including flex-fuel versions, under different letters. If your 2008 truck shows a character not listed here, decode the full VIN.

2015 Silverado 1500

2020 Silverado 1500

These codes are printed in GM's 2020 owner's manual, with the diesel added from vPIC.

2023 and 2024 Silverado 1500

The 3.0L diesel changed RPO code from LM2 to LZ0, and its VIN letter changed with it. For 2023, vPIC also still returns T (LM2), so a 2023 diesel can show either letter. The full decode will tell you which one the truck has.

The GMC Sierra 1500 shares these engines. In vPIC, 2020 Sierra VIN patterns with L decode as the 6.2L L87 and with T as the 3.0L LM2 diesel. Electric models such as the Silverado EV use a separate coding scheme.

Silverado 2500HD engine codes (Duramax and gas)

Heavy-duty buyers usually want to know one thing first: is it a Duramax diesel? The 8th character answers that.

2015 Silverado 2500HD

2020–2024 Silverado 2500HD

In vPIC, 2020 Silverado HD VIN patterns with Y decode as the 6.6L L5P Duramax. vPIC returned the same two codes for 2024.

Both current HD engines are 6.6 liters, so "6.6" on a listing does not tell you whether the truck is gas or diesel. The 8th character does. A 7 truck with a Duramax badge should be questioned before you pay a diesel price.

Tahoe, Suburban, Equinox, Camaro and Corvette

These are the codes vPIC returns for the years shown. We kept only engines Chevrolet offered in each model.

Note how X means the 2.0L turbo on both the Equinox and the Camaro, while X meant a 4.3L V6 on a 2008 Silverado. The letter alone is never enough. Read it with the model and year.

The SPID label: your backup source

GM puts a second record of the engine on the vehicle itself. The 2020 Silverado owner's manual describes it under "Service Parts Identification":

• Newer GM vehicles may have a large barcode on the certification label on the center (door) pillar. Scanning it returns the VIN, model designation, paint information and production options.
• If there is no large barcode on that label, the manual says the same information is on a label inside the glove box.

That glove-box sticker is the Service Parts Identification label, often called the SPID label. Its list of production options includes the RPO codes, so you can find the engine code (for example L84) there even if the VIN is hard to read. On older GM cars the label can sit elsewhere, so check the owner's manual for your model and year.

Use the SPID label or barcode as a cross-check, not a replacement. It should agree with the 8th VIN character. If they do not match, check the VIN and factory options with a Chevrolet or GMC dealer.

How to check the engine on a used Chevy

1. Read the VIN from the vehicle. Use the windshield plate or the door-jamb label, not the listing. Our VIN location guide shows where to look.
2. Find the 8th character and match it to the table for that model and year.
3. Decode the full VIN with our Chevy VIN decoder or the free VIN decoder to get the engine, RPO code, drive type and plant in one step.
4. Check the SPID label or barcode for the engine RPO code and make sure it matches.
5. Look at the engine. Covers and badges can be swapped. Ask whether the engine was ever replaced and get the paperwork if it was. A replacement engine does not change the VIN.
6. Get the original options. A VIN does not reliably show option packages such as a max trailering package. Our guide to the window sticker by VIN explains how to recover the original sticker.
7. Check recalls. Our decoder lists NHTSA recalls for the model and year. Then run the VIN through NHTSA's recall lookup to see open recalls on that exact vehicle.

Shopping a Ford as well? The same 8th-character rule applies, but the letters are different. See our Ford engine code by VIN chart. For Wranglers, Gladiators and Grand Cherokees, our Jeep VIN decoder lists the 8th-character engine codes.