NGK DPR8Z spark plug

key size: 18 mm

external thread [mm]: 12.0

fiber diameter [mm]: 19.0

spark plug: M4 terminal design

spark placement [mm]: 4.5

spark plug: Nickel - middle electrode

spark plug: External electrode

spark plug: suppressed, 5 kOhm

spark plug: with flat sealing seat

The combination of letters and numbers given on each NGK spark plug is not only a type designation, but mainly a logical formula containing important detailed information about the function of the spark plug.

With this formula, NGK has standardized its entire range and is thus able to clearly determine the specific properties of the respective products.

This again simplifies handling and the correct choice of NGK spark plugs, both in the original equipment of the manufacturers, and also later in the shop, in the workshop and with customers.

A typical label is:

The combination of letters (1-4) before the heat value gives information about the diameter of the thread, the size of the hex key and the type of construction.

The 5th position (numerical value) indicates the heat value.

The 6th letter indicates the thread length.

The 7th letter contains data on the special design features of the spark plugs.

The 8th position is again a number in which the electrode distance is coded.