NGK Spark Plug Codes:
NGK code: [B] [P]
[6] [E] [S]
Field one: Thread Diameter
|
A
|
18 mm
|
|
B
|
14 mm
|
|
C
|
10 mm
|
|
D
|
12 mm
|
Field two: Construction
|
C
|
Hex size 5/8"
|
|
K
|
Hex size 5/8" with projected tip (ISO)
|
|
M
|
Compact type
|
|
P
|
Projected insulator type
|
|
R
|
Resistor
|
|
SD
|
Surface discharge for rotary engines
|
|
U
|
semi-surface discharge
|
|
Z
|
inductive suppressor
|
Field three: Heat Range
|
2
|
Hot
|
|
10
|
Cold
|
Field four: Thread reach
|
E
|
19 mm
|
|
F
|
tapered seat
|
|
H
|
12.7 mm (1.5")
|
|
L
|
11.2 mm (7/16")
|
| |
If this field is blank, an 18 mm diameter plug has 12
mm reach; and a 14 mm plug has 9.5 mm (3/8") reach.
|
Field five: Firing and construction
|
A,B
|
Special design (no details given)
|
|
C
|
special ground electrode
|
|
G
|
Racing use
|
|
GV
|
Racing V-type
|
|
H
|
Half thread
|
|
K
|
2 ground electrodes
|
|
L
|
Half heat range
|
|
LM
|
Compact lawn mower type
|
|
M
|
2 ground electrode for Mazda rotary engine
|
|
N
|
Special ground electrode
|
|
P
|
Platinum tip (premium)
|
|
Q
|
4 ground electrodes
|
|
R
|
Delta ground electrode for BMW
|
|
S
|
Standard 2.6 mm electrode
|
|
T
|
3 ground electrodes
|
|
V
|
Fine-wire electrode, gold-palladium
|
|
VX
|
Platinum tip (high performance)
|
|
W
|
Tungsten electrode
|
|
X
|
Booster gap
|
|
Y
|
V-groove centre electrode
|
Field six: Wide gap
|
8
|
.032"
|
|
9
|
.036"
|
|
10
|
.040"
|
|
11
|
.044"
|
|
13
|
.050"
|
|
14
|
.055"
|
|
15
|
.060"
|
|
20
|
.080"
|
|
