How often should the original spark plugs of a Corolla be replaced?

[Warren]

Corolla's original spark plugs should be replaced every 80,000 kilometers. The spark plugs use the Denso brand, with the model number SC20HR11. Spark plugs, commonly known as sparkers, function by discharging the pulsed high voltage electricity delivered by the high-tension leads, breaking down the air between the two electrodes of the spark plug to generate an electric spark, thereby igniting the mixed gas in the cylinder. Currently, spark plugs on the market are broadly divided into three types: ordinary nickel alloy spark plugs, platinum spark plugs, and iridium spark plugs. The Corolla's body dimensions are 4620mm in length, 1775mm in width, and 1480mm in height, with a wheelbase of 2700mm.

[McBeckett]

I remember the factory-recommended replacement interval for Corolla spark plugs is typically between 80,000 to 100,000 kilometers, depending on usage conditions. For my 1.2T model, when it reached 90,000 km, I noticed significantly slower cold starts and fuel consumption increased from 6.5L to 7.2L per 100km. Maintenance inspection revealed the spark plug electrodes were already eroded. The mechanic explained that turbocharged engines wear out spark plugs faster than naturally aspirated ones, especially since I frequently drive short distances in traffic-congested areas where carbon buildup accelerates aging. After switching to iridium spark plugs, the car remains stable even at 140,000 km now. During routine maintenance, remember to ask the technician to check the ignition gap - replacement should be considered when it exceeds 1mm.

[KiraDella]

I've been driving a Corolla Hybrid for three years, and the spark plug replacement cycle for hybrid vehicles is quite unique. The manual suggests replacement at 100,000 kilometers, but I actually changed them at 120,000 kilometers because the electric motor shares a significant workload, resulting in shorter engine operation time. However, don't rely solely on mileage. Once, after a two-week business trip without driving, I noticed a startup delay of over two seconds upon returning, and the ignition coils were covered in carbon dust. I recommend performing a visual inspection of the combustion chamber every two years, especially for those who frequently drive at low speeds. Overly rich air-fuel mixtures can lead to side electrode carbon buildup, causing premature spark plug failure.