Parts for your 2012 Mitsubishi Lancer-Spark plugs

2012 Mitsubishi Lancer Spark Plugs

Technical sources including the Mitsubishi Motors 2012 Lancer Owner’s Manual (maintenance schedule), the Lancer service manual for 4B1-series engines, and AU/NZ catalogues from NGK and Denso confirm that 2012 Mitsubishi Lancer petrol models (2.0L 4B11, 2.4L 4B12, plus turbo variants) use spark plugs. Only the Europe-market 1.8 Di‑D diesel runs glow plugs, not spark plugs. For Australia and New Zealand petrol variants, spark plugs are absolutely relevant and part of normal servicing.

In a 2012 Lancer petrol, the spark plugs light the air‑fuel mix thousands of times a minute, keeping starts crisp, idle smooth, and fuel economy on song. The coil‑on‑plug ignition fires each plug precisely, and the factory iridium plugs are built to last, resist fouling, and keep emissions tidy. When plugs age, the gap grows and the spark weakens, which can mean rough running, flat spots and a thirstier tank.

Most factory iridium plugs in these engines are due around 90,000–100,000 kilometres (check the service book for your exact engine code). Turbo models and hard use can bring that forward. Always fit the correct heat range and design specified by Mitsubishi (NGK and Denso list direct replacements for the 4B11/4B12). Non‑turbo engines typically use an iridium plug with about a 1.0–1.1 mm gap, turbo variants usually run a tighter gap around 0.7–0.8 mm. Don’t force‑regap fine‑wire iridium tips—use the right plug out of the box and confirm specs on the under‑bonnet label or in the owner’s manual.

• Tell‑tale signs it’s time: hesitant acceleration, rough idle, higher fuel use, hard starts, or a check‑engine light with misfire codes.
• Best practice: change all four at once, inspect coil boots, and add a light dab of dielectric grease inside the boots.
• Installation: let the engine cool, blow out plug wells, and torque to spec (typically around 18–21 Nm for gasketed plugs in an alloy head). Modern plated threads usually don’t need anti‑seize.

A fresh set of correctly‑specced plugs helps the Lancer feel perkier, start better on cold mornings, and keeps the cat and coils happy. It’s a small job that pays off in smooth, efficient motoring right across Aussie and Kiwi conditions.

How often should the spark plugs be replaced on a 2012 Lancer?

For the 2.0L/2.4L petrol engines with factory iridium plugs, plan around 90,000–100,000 km or about 6 years. Turbo models and severe use may need them earlier. Always follow the schedule in the Mitsubishi owner’s manual for your exact engine.

What spark plug type and gap does it use?

Use OEM‑equivalent iridium plugs in the correct heat range for the 4B11/4B12 (as listed by Mitsubishi, NGK or Denso). Non‑turbo engines typically run about 1.0–1.1 mm, turbo variants about 0.7–0.8 mm. Confirm on the under‑bonnet sticker or in the manual. Avoid forcing gaps on fine‑wire iridium plugs.

What happens if worn plugs aren’t replaced?

Misfires can hammer the ignition coils, waste fuel, and overheat the catalytic converter. Leaving it too long often costs more than a timely plug change—expect smoother running and better economy once they’re refreshed.