Identifying DENSO Plugs

IRIDIUM POWER Series (Power, Tough, Plus) & TT

High Performance Plug

I	0.4 mm diameter iridium <POWER>
V	0.4 mm diameter iridium with platinum tip <TOUGH>
VF	0.4 mm diameter iridium with 0.7 mm needle type platinum tip <TOUGH>
VD	0.7 mm diameter iridium with 0.7 mm needle type platinum tip <TOUGH>
P	1.1 mm platinum center electrode
VS	0.7 mm diameter iridium with platinum tip <TOUGH>

Thread Diameter, Reach, and Hex Size

K	14×19.0×16.0	XU	12×19.0×16.0
KB	14×19.0×16.0 (New Triple Electrodes)	XUH	12×26.5×16.0
KA	14×22.0 (Shroud 3.0)×16.0 (New Triple Electrodes)	CH	12×26.5×14.0
KD	14×20.5 (Shroud 1.5)×16.0	XEH	12×26.5×14.0
KH	14×26.5×16.0	XEBH	12×26.5×14.0 (New Triple Electrodes)
KBH	14×26.5×16.0 (New Triple Electrodes)	X	12×19.0×18.0
Q	14×19.0×16.0	XG	12×21.8 (Shroud 2.8)×18.0
W	14×19.0×20.6	XEHC	12×28 (Shroud 1.5)×14
WF	14×12.7×20.6	U	10×19.0×16.0
WM	14×19.0×20.6 (Compact Insulator)	UF	10×12.7×16.0
T	14×17.5 (Taper Seat)×16.0	UH	10×19.0 (Half Thread)×16.0
TF	14×11.2 (Taper Seat)×16.0	NH	10×19.0 (Half Thread)×16.0
TL	14×25.0 (Taper Seat)×16.0 (Long Insulator)	UEH	10×26.5×14
TV	14×25.0 (Taper Seat)×16.0	Y	8×19.0 (Half Thread)×13.0

Heat Range

DENSO	NGK	CHAMPION	BOSCH
16	5	12,11	8
20	6	10,9	7,6
22	7	8,7	5
24	8	6,63,61	4
27	9	4,59	3
29	9.5	57
31	10	55	2
32	10.5	53
34	11
35	11.5

Shape (Type)

A	Slant electrode, No U-Groove, No taper cut	I	Spark position: 4 mm Projected insulator (1.5 mm)
B	Projected insulator (1.5 mm)	J	Spark position: 5 mm
C	No U-Groove	K	Spark position: 4 mm Projected insulator (2.5mm)
D	No U-Groove	L	Spark position: 5 mm
E	Shroud: 2 mm	T	For LPG applications <PLUS>
ES	Stainless steel gasket	TT	TT series
F	Special specification	Y	0.8 mm gap
G	Stainless steel gasket, Terminal one type	Z	Taper cut

Iridium Plugs / Platinum Plugs / Normal Plugs

Type of precious metal

D	0.7 mm diameter iridium with 0.7 mm needle type platinum
F	0.55 mm diameter iridium with 0.7 mm needle type platinum
P	1.1 mm diameter platinum with platinum tip
S	0.7 mm diameter iridium with platinum tip
SV, V	0.4 mm diameter iridium with platinum tip
Z	0.55 mm diameter iridium with platinum tip
E	0.7 mm diameter iridium with 1.0 mm needle type platinum

Thread Diameter and Hex Size

C	12×14.0	S	14×20.6 (Surface gap plug(for RE engines))
L	18×22.2 (Reach: 12.7 mm)	T	14×16.0 (Taper seat)
M	18×25.4 (Reach: 12 mm)	W	14×20.6
MA	18×20.6 (Taper seat, Reach: 12 mm)	W	14×19.0 (Compact type)
MW	18×20.6 (Reach: 12 mm)	X	12×18.0
J	14×20.6 (Projected plug)	XE	12×14.0
K	14×16.0 (Miniature plug)	XU	12×16.0
KJ	14×16.0 (Projected Miniature plug)	N	10×16.0
LP	14×20.6 (Plug for LPG applications)	U	10×16.0
Q	14×16.0 (Miniature plug)	Y	8×13.0
QJ	14×16.0 (Projected Miniature plug)	XB	12×(Bi-hex)
QL	14×20.6 (Miniature long cylinder housing plug)	UE	10×14

Heat Range

DENSO	NGK	CHAMPION	BOSCH
4
9	2	18	10
14	4	16,14	9
16	5	12,11	8
20	6	10,9	7,6
22	7	8,7	5
24	8	6,63,61	4
27	9	4,59	3
29	9.5	57
31	10	55	2
32	10.5	53
34	11
35	11.5

Reach

A	19.0 mm (Spark position: 7.0 mm) J16AR-U11	G	22.0 mm (Shroud 3.0) PK20GR8
A	21.5mm S29A	G	21.8 mm (Shroud 2.8) X27GPR-U
B	19.0 mm (Spark position: 9.5 mm) J16BR-U	H	26.5mm K16HPR-U11
C	19.0 mm (Spark position: 5.0 mm) KJ20CR-L11	H	19.0 mm (Spark position: 8.5 mm) QJ16HR-U
D	20.5 mm (Shroud 2) K20DTR-S11	L	11.2mm W14L
E (With gasket)	19.0 mm W16EX-U	N (Taper seat, Half thread)	17.5mm T20NR-U11
E (With gasket)	20.0 mm W25EBR	V (Taper seat)	25mm PT16VR13
E	Shroud 2.0mm FXE20HE11	None	9.5 mm W14M-U 11.2 mm L14-U, M24S 19mm SK20R11 21.5 mm S29A
F	12.7mm W20FP-U	None (Taper seat)	8.3 mm T20M-U 11.2 mm W14L
FE	19.0 mm (Half thread) U24FER9

Shape (Type)

A	Double ground electrodes W22EA	P	Projected (1.5 mm projection) W16EP-U
AY	Double ground electrodes with bent shape J16AY	Q	Projected 2mm, Spark position 3.5mm
B	Triple ground electrodes W22EB	R	5Kohm resistor K16R-U
BG	Triple ground electrodes (shroud) SK20BGR11	S	Non-projected (0 mm Projection) W22ES-U
C	Shroud 1.5mm SXU22HCR11	S	Iridium on a single side KJ20SR11
D	4 ground electrodes W27EDR	T	Double ground electrodes K16TR11
D	Projected (1.5 mm projection, spark position 3.5 mm) XU22HDR9	TM	Double ground electrodes K22TMR11
K	Projected (1 mm projection) W16EKR-S11	TN	Double ground electrodes K22TNR-S
LM	Compact type (Hex 20.6 mm) W14LM-U	X	Fully projected (2.5 mm Projection) W16EX-U
M	Shortened insulator head length W27EMR-C
M	Compact type (Hex 19.0 mm) W20M-U

Shape (Type)

-A	Special specification SK16PR-A11	-N	For Yamaha and Kawasaki U27ESR-N
-B	Special specification K16PSR-B8	-P	Double Platinum Ground Electrode SK20R-P11
-C	Cut-back ground electrode W27EMR-C	-P	Single-sided platinum plug K16PR-P11
-CY	Special specification FC16HR-CY9	-Q	Special specification FC16HR-Q8
-D	Copper-core Ground DK20PR-D13	-R	10K ohm resistor K22PR-UR
-E	Special specification SK16PR-E11	-S	Semi-surface gap discharge type W20EP-S11
-F	Special specification J17SK16PR-F11	-S	Stainless gasket U27FER9S
-G	Grease applied on to threads, for CNG SK20R8-G	-T	For LPG SK20HR8-T
-GL	Platinum center electrode X22EPR-GL	-T	Special specification FK20HBR11-T
-L	Heat resistant ground electrode K20PR-L11	-TP	Taper-cut, single-side platinum plug K20PR-TP11
-L	3.5 mm projected insulator for motorcycles W20FP-UL	-U	U groove ground electrode K16PR-U
-L	Retracted insulator for motorcycles W20FR-L	-V	1.3 mm diameter, nickel center electrode W27ES-V
-M	Larger ground electrode SK20PR-M11S

Gap

5	0.5mm (.020”)
8	0.8mm (.032”)
9	0.9mm (.035”)
10	1.0mm (.040”)
11	1.1mm (.044”)
13	1.3mm (.050”)
14	1.4mm (.055”)
15	1.5mm (.060”)

<None> Cars: 0.8 mm M/C: 0.7 mm
<Exceptions> P16R, PQ16R, PQ20R are 1.1 mm

IRIDIUM RACING

Warning: On choosing the right racing plug

Generally, electrodes that project into the combustion chamber have better ignitability and have better performance. However, because of more exposure to high temperature combustion gases and because ground electrode becomes longer, heat resistance and durability decrease. The higher the level of tuning, the greater the need is to use a less projecting type.
As the level of tuning is increased, so does the need for higher heat range.

I	W	0	1	ー	27
↑	↑	↑	↑		↑
Variety	Thread Size	Intermediate Number （Overall Size）	Intermediate Number （Electrode Shape）		Heat Range
I：Iridium	U：10mm		1：Slant ground electrode or surface gap plug.		24
	XU：12mm				27
	A：14mm				29
R：Surface Gap	AE：14mm		2：Flat ground electrode		31
	K：14mm		2：Flat ground electrode		32
	KH：14mm		6：Slant ground electrode and non-resistor plug		34
	Q：14mm				35
	RE：14mm
	RL：14mm		(Exception) IRE01 has a flat ground electrode.
	RT：14mm
	W：14mm
	WM：14mm