⚡Spark Plug Type
Hummer H3 Spark Plug Type
Find the correct spark plug type, gap size, and replacement interval for your Hummer H3. Covers all model years with torque specs.
Quick Answer
The Hummer H3 typically uses iridium or platinum spark plugs. Newer models (2010+) use long-life iridium plugs rated for 60,000-100,000 miles. Check below for your specific year.
2006-2010
2006-2010Spark Plug TypePlatinum or Iridium
Plug Gap0.039" - 0.044" (1.0 - 1.1mm)
Replacement Interval30,000 - 60,000 miles
Torque Spec13 - 20 ft-lbs
Quantity4 (inline-4) or 6 (V6)
Notes
- →Iridium plugs last longer but cost more — do NOT re-gap iridium plugs
- →Use a torque wrench — over-tightened plugs can strip aluminum heads
- →Apply a thin coat of anti-seize to threads (unless plug is pre-coated)
- →Use a spark plug socket with rubber insert to avoid cracking the ceramic insulator
Frequently Asked Questions
- What spark plugs does a Hummer H3 use?
- The Hummer H3 spark plug type varies by year and engine. Newer models (2010+) typically use iridium plugs for longer service life. Older models may use platinum or copper. Check the specs below for your exact year.
- How often should I change spark plugs on a Hummer H3?
- Modern Hummer H3 models with iridium plugs can go 60,000-100,000 miles between changes. Older models with copper plugs need replacement every 30,000 miles. Replace sooner if you notice misfires, rough idle, or poor fuel economy.
- What is the spark plug gap for a Hummer H3?
- Most Hummer H3 models use a spark plug gap between 0.039" and 0.044" (1.0-1.1mm). Pre-gapped plugs from the OEM are recommended. Do not re-gap iridium-tip plugs as it can damage the electrode.
- Can I upgrade to iridium spark plugs in my Hummer H3?
- Yes, upgrading from copper or platinum to iridium is generally safe and beneficial. Iridium plugs offer better ignitability, longer life, and improved fuel economy. Just match the correct heat range and gap for your engine.