Racing Plugs Comparison Chart

Size Heat Range Champion AC Motorcraft Bosch Lodge NGK K.L.G.
14mm L-88A S42F AE 2x W175 T1 2HN B7 HS
1/2 inch reach L-81 S41F AE 1X W240 T1 3HN B8 HS
standard gap L-78 W260 S11S
L-77J S40F AE901x W260 T1 B9 HS
14mm L-62R AE23 X240 S1S R47 B8 HN F 220/F250
1/2 inch reach L-60R AE903 W260 S1S R49 B9 HN F 260
L-57R AE603 W280 S1S/W310 S1S R50 B10 HN F 280
L-54R AE403 W340S1S/W370 S1S R51 B11 HN F 320
AE203 F 340
14mm N-5 44 N AG3 W175 T2 HNLHL 14 B6 ES FE 70
3/4 inch reach 44 XL HLNP FE 75
N-4 C42N/C41N AG2 W225 T2 2HLN B7 ES FE 80
N-3 43 XL AG901 W260 T2 3HLN B8 ES FE 100
N-2 S41 XL AG701 W260 T2 3HLN B9 ES FE 220
N-60 AG701 B10 ES
N-57 AG501
14mm N-66Y AG22 2 HLNY
3/4 inch reach N-7Y/N65Y AG12 2 HLNY
P.C.N. N-6Y/N-64Y W260 T28 3 HLNY B77 EC FE 125P
N-63Y 4 HLNY
N-60Y 5 HLNY
14mm N-4G S43 XL AG2M WG235 T28 BP6 EV
3/4 inch reach N-3G S42 XL W250 P21 BP7 EV
Gold Palladium N-2G S41 XL W265 P21 BP8 EV
N-59G/N-84G BP8 EV
N-57G/N-82G BP9 EV
N-5G/N-80G BP10 EV
14mm N-62R AG 23 W240 S2S RL47 B8 EN FE 220
3/4 inch reach N-60R AG 903 W260 S2S RL49 B9 EN FE 260
N-57R AG 603 W310 S2S RL50 B10 EN FE 280
N-54R AG 403 W340 S2S RL51 B11 EN FE 310
N-52R/N77R AG 203/AG 103 W370 S2S/W400S2S RL53 B12 EN FE 340
14mm J-6J M44 C A3X W225 T3 HAN B6 FS 75H
3/8 inch reach M44 A3XM HANP
J-4J AT2/A21XM W240 T3 2HAN B7 FS 100H
M42 K A2X/A21X
J-2J M41 K/M41G AT1 W260 T3 3HAN B77 C FP 100
J-79 A901
14mm UJ-10Y C44 S AT 42 W145 T7 CANY BP-6 FP 55P
3/8 inch reach 435 A 32
P.C.N. J-63Y 425 A 22
J-61Y C421 A12

You may also like to read an article about Racing Plugs by Keith Gough, Development Engineer at K.L.G.

Oliver Lodge (1851 - 1940) invented electric spark ignition (the Lodge Igniter). His two sons developed the idea and founded the Lodge Plug Company. Lodge is also known for his pioneering work in radio and was the first man to transmit a message by wireless.