2016 Toyota Highlander Spark Plug Type, Gap & Torque

Quick reference

Why the right plug matters

Choosing the correct spark plugs for your 2016 Toyota Highlander is crucial for optimal engine performance, fuel efficiency, and to prevent costly damage. Spark plugs are designed to ignite the air-fuel mixture in your engine's combustion chambers, and their precise design ensures proper combustion under various operating conditions.

Heat Range: Spark plugs are manufactured with a specific "heat range," which refers to their ability to dissipate heat. A plug that's too hot can lead to pre-ignition and engine knocking, while a plug that's too cold can cause fouling and misfires. Automakers carefully select the appropriate heat range for each engine, making it essential to stick to the recommended OEM or equivalent aftermarket plugs.

Electrode Metal: The material of the spark plug's electrode significantly impacts its lifespan and performance:

• Iridium: Most modern vehicles, including your 2016 Highlander, come equipped with iridium spark plugs. Iridium is an extremely hard and durable metal, allowing for very fine electrodes that create a more focused spark. This leads to better fuel efficiency, more consistent idle, and significantly longer service intervals (typically 100,000 to 120,000 miles).
• Platinum: Platinum plugs offer good durability and performance, often lasting around 60,000 miles. They are a step up from traditional copper plugs but generally don't match the longevity or precision of iridium.
• Copper: Copper spark plugs have the best conductivity but are softer and wear out more quickly, typically requiring replacement every 20,000 to 30,000 miles. While cheaper upfront, their shorter lifespan makes them less economical in the long run for vehicles designed for longer-lasting materials.

How to gap a spark plug

The spark plug gap is the distance between the center and ground electrodes. This gap is critical for a strong, consistent spark. While many modern iridium spark plugs come pre-gapped, it's always a good idea to double-check, especially if you're using a non-OEM plug.

To check and adjust the gap:

1. Use a wire gauge tool: A wire-type spark plug gapping tool is generally preferred for iridium and platinum plugs as it's less likely to damage the delicate electrode.
2. Slide the gauge: Carefully slide the appropriate wire gauge (0.043 inches or 1.1 mm for your Highlander) between the electrodes. There should be a slight drag.
3. Adjust if necessary: If the gap is too small, use the gapping tool's lever to gently bend the ground electrode outwards. If the gap is too large, gently tap the ground electrode on a hard surface to close it. Be extremely careful not to touch or bend the fine center iridium electrode, as it can be easily damaged.

Replacement procedure tips

Replacing spark plugs on your 2016 Toyota Highlander, whether it