Standard copper spark plugs should be replaced every 30,000 miles. Iridium and platinum plugs can last 60,000-100,000 miles. Always check your vehicle owner's manual for the recommended interval.

Common symptoms include rough idle, engine misfires, poor fuel economy, sluggish acceleration, and difficulty starting. A check engine light with misfire codes (P0300-P0312) often indicates spark plug issues.

Yes. Denso is one of the world's largest OEM auto parts manufacturers, supplying original equipment to Toyota, Honda, Chrysler, GM, Ford, and many other automakers.

Denso spark plugs come pre-gapped from the factory for most applications. However, it is always good practice to verify the gap matches your vehicle's specification before installation.

DENSO Iridium spark plugs feature an ultra-fine 0.4mm iridium center electrode that requires less voltage to fire, provides more consistent spark, and lasts up to 100,000 miles. The iridium tip resists wear better than copper or platinum.