2017 Jeep Grand Cherokee Spark Plug Type & Gap

Quick reference

Why the right plug matters

Choosing the correct spark plug for your 2017 Jeep Grand Cherokee is crucial for optimal engine performance, fuel efficiency, and longevity. The "right" plug isn't just about fitment; it's about the right heat range and electrode metal.

Heat range refers to a spark plug's ability to dissipate heat from the combustion chamber. A plug that's too "cold" (dissipates heat too quickly) can lead to carbon fouling, while a plug that's too "hot" (dissipates heat too slowly) can cause pre-ignition and detonation, severely damaging your engine. Manufacturers specify a particular heat range to match the engine's design and operating conditions. Sticking to the OEM-recommended heat range is always the safest bet.

Electrode metal significantly impacts a spark plug's lifespan and performance:

• Copper: These are excellent conductors of electricity and heat, making them a good choice for consistent spark delivery. However, copper is a soft metal and wears down relatively quickly, typically requiring replacement every 30,000 miles. Many performance applications and older engines still utilize copper plugs due to their robust spark.
• Platinum: Platinum is much harder and more durable than copper, allowing for finer electrode designs and longer life spans—often up to 100,000 miles. These are common in many modern vehicles, including the 3.6L Pentastar V6 when equipped with specific platinum plugs from the factory.
• Iridium: The hardest and most durable of the three, iridium allows for the finest wire electrodes, which produce a very concentrated and efficient spark. Iridium plugs typically offer the longest service intervals, often exceeding 100,000 miles. Some high-performance engines, like the 6.4L SRT HEMI, use iridium plugs due to their precise spark and durability under extreme conditions, though the service interval for the 6.4L is more aggressive due to the nature of the high-performance application.

How to gap a spark plug

Correctly gapping a spark plug ensures a strong spark, which is vital for efficient combustion. While many modern spark plugs, especially iridium and platinum, come "pre-gapped," it's always a good idea to double-check the gap before installation. This is especially true for copper plugs.

To gap a spark plug, you'll need a spark plug gap gauge tool, which comes in various forms (wire-type or coin-type). For platinum and iridium plugs, use extreme caution, as bending the fine electrode can easily damage it. It