AC Delco MR43LTS Iridium Spark Plug - Interchanges with NGK TR5, Donovan 203264

The AC Delco MR43LTS is an iridium spark plug built for reliable cold starting, quick acceleration, and smooth engine performance. The electrode uses a nickel alloy tip paired with a copper core, and a ribbed suppressor seal is engineered for durability and consistent performance over the life of the plug. Iridium construction gives the MR43LTS a high melting point and strong resistance to the extreme heat and pressure inside the combustion chamber, helping the plug maintain a stable spark and resist electrode wear longer than plugs using softer tip materials.

The MR43LTS is built to AC Delco's standard fit, form, and function for applications that call for this plug or its cross-referenced equivalents, including the NGK TR5 and Donovan 203264. It is a direct, drop-in option for engines and rebuild kits specifying any of those part numbers.

Specifications

• Brand: AC Delco
• Manufacturer Part Number: MR43LTS
• UPC: 808709617211
• Construction: Iridium
• Electrode Tip Material: Nickel alloy
• Core Material: Copper
• Seal: Ribbed suppressor seal
• Interchangeable With: NGK TR5
• Weight: 0.1 pounds

Replaces (OEM)

• Donovan 203264
• NGK TR5

Frequently Asked Questions

What does the NGK cross-reference number mean for the AC Delco MR43LTS? The AC Delco MR43LTS is interchangeable with the NGK TR5, so either part number can be used to order the correct spark plug for an application that lists one or the other.

Is the Donovan 203264 the same spark plug as the AC Delco MR43LTS? Yes, Donovan 203264 is a listed cross-reference for the AC Delco MR43LTS, meaning the two part numbers identify the same plug for ordering purposes.

What is the electrode tip made of on the MR43LTS spark plug? The MR43LTS uses a nickel alloy electrode tip paired with a copper core, a combination chosen for durability and consistent performance.

How much does the AC Delco MR43LTS weigh? The AC Delco MR43LTS spark plug weighs 0.1 pounds.

Why is iridium used in the MR43LTS spark plug? Iridium construction gives the MR43LTS a high melting point and added strength, which supports reliable cold starting, quick acceleration, and smooth engine performance.

What type of seal does the MR43LTS spark plug use? A ribbed suppressor seal is used on the AC Delco MR43LTS to support durability and consistent performance over the life of the plug.

Is the AC Delco MR43LTS a genuine AC Delco part or an aftermarket copy? The MR43LTS is a genuine AC Delco spark plug, not a third-party aftermarket copy, identified by AC Delco part number MR43LTS and UPC 808709617211.

How do I know if the MR43LTS is the right spark plug for my engine? Match the AC Delco MR43LTS against your current spark plug's part number or its NGK TR5 or Donovan 203264 cross-reference to confirm it is the correct replacement.

What is included when I order the AC Delco MR43LTS? Each order of the AC Delco MR43LTS includes one iridium spark plug, part number MR43LTS.

Does the MR43LTS help with cold starting? Yes, the iridium construction of the AC Delco MR43LTS is designed for reliable cold starting along with quick acceleration and smooth engine performance.

How is the MR43LTS different from the AC Delco MR43T spark plug? The MR43LTS and MR43T are separate AC Delco spark plug part numbers with different OEM cross-references, so they are not interchangeable; confirm which part number your application calls for before ordering.