Why Iridium Spark Plugs Are Worth the Extra Cost

Iridium spark plugs cost more than copper or platinum — sometimes 3–5x the price. But for most drivers with modern vehicles, iridium plugs are actually the more economical choice over time. Here's why.

The Science Behind Iridium

Iridium is one of the hardest metals on earth — harder than platinum, far harder than copper. This allows manufacturers to use an ultra-fine center electrode tip (as small as 0.4mm on premium plugs) that:

• Requires less voltage to fire (less strain on ignition coils)
• Creates a more focused, efficient spark
• Wears extremely slowly (hence the long service interval)

Performance Benefits

Iridium's fine tip creates a more precise spark that ignites the air-fuel mixture more completely. Real-world results include:

• Sharper throttle response, especially at low RPMs
• Improved fuel economy (1–3 MPG improvement vs. worn copper plugs)
• Smoother idle
• Better cold-start performance

The Math on Cost

A set of copper plugs for a 4-cylinder: ~$12, replaced every 30,000 miles = $24 per 60,000 miles plus 2x labor. A set of NGK Iridium IX: ~$40, replaced every 60,000 miles = $40 per 60,000 miles plus 1x labor. Iridium saves money even before considering labor costs.

Best Iridium Options

• NGK Iridium IX — Best value iridium, excellent for most applications
• NGK Laser Iridium — OEM-grade, fine iridium tip, 60,000-mile life
• Champion Iridium — Competitive quality at a slightly lower price point

Shop iridium spark plugs at Texan Supply with free shipping.