Can we just change one spark plug?
Usually the mechanic will replace all of them. In theory, even if it is replaced with the same brand of the same model, the discharge gap between the new and old spark plugs is not the same, the resistance value of the new and old spark plugs is not the same, not all replacement will appear shaking, acceleration difficulties, increased fuel consumption and other problems, meaning that the spark plug may be different resulting in different ignition Angle energy, resulting in four cylinder power imbalance.
There is a spark plug has a certain life, the same batch of product quality and life should be very close, since there are one or two problems, indicating that other spark plugs are approaching. So replace them together, just in case.
Now common electrode materials on the market are copper, nickel alloy, white gold, iridium gold four (white gold and iridium are commonly called precious metals), metal conductivity from left to right increased (copper < nickel alloy < white gold < iridium), ignition required voltage from left to right decreased (copper > nickel alloy > white gold > iridium), so the precious metal spark plug for the engine load is smaller, It is beneficial to reduce fuel consumption; In addition, the service life of precious metals is also longer, of course, the price is also increased with the increase of performance.
