| With
standard central copper, platinum, or iridium electrode (new).
| Highly tuned engines need
colder spark plugs (where NGK spark plugs are used, install plugs with a higher
heat range index number than the stock units). If you do not know the correct
heat range, it's best to install a fairly cool plug. If the spark plug tends to
foul during operation and thus causes misfiring, change to a spark plug with a
slightly lower index number. For obvious safety reasons, the rule of thumb is
to use the coldest plug that the engine can tolerate without leading to fouling. |
| | |
Standard NGK spark plugs |
| |
Iridium NGK spark plugs |
Platinum NGK spark plugs |
|