The spark plugs in most 2018 Silverado models are designed to last about 100,000 miles under normal driving conditions. If you tow frequently, operate in dusty or extreme climates, or do a lot of short trips, you may need to replace them earlier, typically around 60,000–90,000 miles.
This article explains the recommended replacement intervals for the Silverado’s main engines (4.3L V6, 5.3L V8, and 6.2L V8), what counts as normal versus severe driving, and signs that plugs may be worn and require attention.
Recommended replacement intervals
Below are the general guidelines that apply to the Silverado’s common engines, noting that actual schedules can vary with driving style and warranty considerations.
- Normal driving: 100,000 miles (160,000 km) for the 2018 Silverado engines when using the recommended long-life spark plugs.
- Severe driving: 60,000–90,000 miles (96,000–145,000 km) if you regularly tow heavy loads, drive in dusty environments, deal with extreme temperatures, or accumulate lots of short trips.
Routine inspection at intervals defined by GM or your service advisor can help catch worn plugs before they cause misfires, poor fuel economy, or other engine issues.
Engine variants and plug replacement guidance
4.3L V6
The 4.3L V6 in the Silverado typically uses long-life plugs with a replacement interval near 100,000 miles under normal conditions. Severe service—such as towing, heavy idling, or dusty environments—may warrant earlier inspection and potential replacement around 60,000–90,000 miles.
5.3L V8
The 5.3L V8 follows the same general guidance: about 100,000 miles under normal operation with the recommended plugs. If you tow regularly or drive in demanding conditions, check around 60,000–90,000 miles and replace as needed.
6.2L V8
The 6.2L V8 also targets a 100,000-mile replacement interval for normal driving. In severe service—towing, frequent heavy use, or extreme climates—plan for earlier inspection and potential replacement within the 60,000–90,000 mile range if symptoms appear.
What to watch for and how to replace
Watch for signs that spark plugs are worn or fouled, including rough idle, misfires, reduced acceleration, hard starting, increased fuel consumption, or the check engine light. If you notice any of these, have the plugs tested and replaced if necessary. When replacing, use the recommended plug type for your engine and follow the factory torque and gap specifications from the owner's manual or service manual.
Summary
In summary, a 2018 Chevy Silverado is generally equipped to reach about 100,000 miles between spark plug changes under normal conditions. If your driving involves frequent towing, dusty environments, or severe conditions, expect to replace them closer to 60,000–90,000 miles. Always verify the exact interval and plug type in your owner's manual and consult a qualified mechanic if you’re unsure about performing the replacement yourself.
How often should I change the spark plugs on my 2018 Chevy Silverado?
every 30,000 miles
The short answer is that you should have them changed every 30,000 miles, but there's more to consider. If you have any other automotive questions, consult our FAQ!
What kills spark plugs quickly?
Pre-ignition can lead to heat building up in the combustion chamber causing the spark plugs to fail. In addition, if the cooling system isn't functioning correctly, it can cause the engine and spark plugs to overheat. This overheating can lead to the spark plug's electrode wearing out faster.
How long do spark plugs last on a Chevy Silverado?
However, changing spark plugs every 30,000 to 100,000 miles or every 3 to 5 years is typically recommended as a general guideline. Always check your owner's manual or contact our service team to get more specific information about your Chevy truck or SUV.
What year 5.3 to stay away from?
What are the worst 5.3 AFM years to avoid? Based on Reddit owner reports, the most commonly avoided years are 2007–2010, 2014–2018, and 2019–2021 Silverado 1500 models with AFM or early DFM. These years show the highest concentration of lifter failure threads.