Spark Plug - HKS M40i - Grade 8

  • Sale: 0% Off
  • Regular price £17.51 (Ex-vat : £14.59)

Stock status: 7 In stock



HKS Mi-Series Super Fire Racing Spark Plug - M40i Grade 8

Note - Price is for 1 single spark plug

HKS Mi-Series Super Fire Racing spark plugs are high performance Iridium plugs designed to handle advanced levels of tuning and provide Improved ignition performance, durability and anti-carbon build-up.

HKS Mi Series Spark Plug Features:

  • 0.6mm Iridium Alloy Centre Electrode. Iridium Alloy Centre Electrode reduces voltage requirement as well as improving ignition performance and durability.
  • Outer Electrode with Platinum Chip. The Outer Electrode incorporates a square platinum chip which improves durability, and when combined with the iridium centre electrode boosts ignition performance.
  • Short Type Outer Electrode (Anti-Vibration). The outer electrode has been shortened and engineered with the ideal shape to decrease weight for resistance against vibration. This anti-vibration design improves longevity of the outer electrode.
  • Thermal Edge: After long idling or various combustion conditions carbon buildup can occur causing misfires. The Thermal Edge of the ceramic insulator will discharge to help decrease carbon deposits.
  • Spark Support Gap: Discharges will occur in the Spark Support Gap (space between the tip of insulator and the base of the outer electrode) to help prevent carbon buildup.
  • Heat Range: 8


Fensport Tip: How to choose a sparkplug grade. (Guide Only)

For NA Cars:

Usually use a grade 6 for most road applications, a grade 7 can be used in hi compression race type cars, grade 8 in extreme rev/compression cars.

For Turbo Cars:

Grade 6 is usually for standard cars, Grade 7 mild upgrades usually 1.2 bar boost, Grade 8 above 1.2bar, Grade 9 above 1.6

Nitrous Oxide:

Usually a colder grade plug is often used when using nitrous oxide.

If you need help please call for details


  • Black Friday 23
  • Honda Civic Type R - EP3 - 08/01> 06/06
  • Honda Civic Type R - FN2 - 06/07> 03/12
  • Honda Civic Type S - EV1 - 10/02> 03/06
  • Honda Civic Vtec - EF9 - 08/89> 08/91
  • Honda Civic Vtec - EG6 - 09/91> 09/95
  • Honda CRZ 1.5 - ZF13 - 02/10>
  • Honda Integra Type R - DC2 - 10/95> 06/01
  • Honda Integra Type R - DC5 - 07/01> 12/04
  • Honda S2000 2.0 AP1 - 04/99> 12/05
  • Honda S2000 2.2 AP2 - 12/05>
  • Kit Car 4A-GE 1600cc
  • Lotus Exige 111R 01/04>
  • Mazda MX5 1.6 Mk1 NA6CE NA18C - 09/89> 93/09
  • Mazda MX5 1.6 MK2 NB6C NB186 01/98>08/05
  • Mazda MX5 1.8 MK1 NA8C & NA18P - 09/93> 01/98
  • Mazda MX5 1.8 Mk2 NB8C NB18P - 01/98> 05/08
  • Mazda MX5 1.8 Mk3 NC188 07/05> 05/15
  • Mazda MX5 2.0 Mk3 NCEC NC*8F 07/05> 05/15
  • Mitsubishi FTO Mivec - 10/94> 07/00
  • Mitsubishi GTO Z16A - 10/90> 07/00
  • Mitsubishi VR4 Galant - Legnum - 08/96> 12/02
  • Nissan 180-200SX-S13
  • Nissan 200SX S14 - 10/93> 01/99
  • Nissan 200SX S15 - 01/99> 08/02
  • Nissan 300ZX Z32 - 07/89> 07/02
  • Nissan Pulsar GTiR - 08/90> 01/95
  • Nissan Skyline GTR R32 08/89> 11/94
  • Nissan Skyline GTR R33 01/95> 01/99
  • Nissan Skyline GTR R34 01/99> 08/02
  • Nissan Skyline GTS R32 05/89> 08/93
  • Nissan Skyline GTS R33 08/93> 05/98
  • Nissan Skyline GTT R34 06/98> 06/01
  • Nissan Stagea C34 09/96> 10/01
  • Subaru Forester SF5 04/98> 01/02
  • Subaru Forester SG5 - SG9 - 02/02> 12/07
  • Subaru Imprezza GC8 & GF8 - 01/93> 08/00
  • Subaru Imprezza GDA to GDF- 08/00> 06/07
  • Subaru Legacy 2nd Gen - BD5 & BG5 - 08/94> 12/98
  • Suzuki Swift Sport ZC31S M16A 09/05>
  • Toyota Altezza RS200 Beams
  • Toyota Aristo 3.0 TT Vertex - JZS147 - 10/91> 08/97
  • Toyota Aristo 3.0 TT Vertex - JZS161 - 08/97> 12/04
  • Toyota Celica 2.0 GT ST182 08/89> 03/94
  • Toyota Celica 2.0 GT ST202 04/94> 10/99
  • Toyota Celica GT4 ST165 01/88> 12/90
  • Toyota Celica GT4 ST185 10/89> 03/94
  • Toyota Celica GT4 ST205 02/94> 08/99
  • Toyota Celica VVTi 140BHP ZZT230 12/99> 05/07
  • Toyota Celica VVTLi 190BHP ZZT231 08/00> 05/07
  • Toyota Corolla 1.6 20 Valve AE101 01/91> 05/95
  • Toyota Corolla 1.6 20 Valve AE111 05/95> 12/00
  • Toyota Corolla 1.6 GT AE82
  • Toyota Corolla 1.6 GT Coupe AE86 05/85> 12/87
  • Toyota Corolla 1.6 GT Coupe AE86 08/83 > 05/85
  • Toyota Corolla 1.6 GTi AE92 05/87> 08/89
  • Toyota Corolla 1.6 GTi AE92 89 to 92
  • Toyota Corolla 1.8 T-Sport ZZE123 11/01> 06/07
  • Toyota JZX100 2.5 Turbo 09/96> 06/01
  • Toyota JZX110 2.5 Turbo 10/00> 06/07
  • Toyota JZX90 2.5 Twin Turbo 10/92> 08/96
  • Toyota Levin / Trueno 1.6 Supercharged AE101 06/91> 05/95
  • Toyota Levin / Trueno 1.6 Supercharged AE92 05/87> 06/91
  • Toyota MR2 2.0 GT Rev 1 3S-GE 12/89> 12/91
  • Toyota MR2 2.0 GT Rev 2 3S-GE 12/91> 11/93
  • Toyota MR2 2.0 GT Rev 3 3S-GE 11/93> 12/99
  • Toyota MR2 MK1 AW11 06/84> 08/86
  • Toyota MR2 MK1 AW11 08/86> 12/89
  • Toyota MR2 MK1 AW11 Supercharger 08/86> 12/89
  • Toyota MR2 Turbo Rev 1 3S-GTE 12/89> 12/91
  • Toyota MR2 Turbo Rev 2 3S-GTE 12/91> 11/93
  • Toyota MR2 Turbo Rev 3 3S-GTE 11/93> 08/99
  • Toyota Soarer 2.5 Twin Turbo JZZ30 05/91> 06/99
  • Toyota Starlet 1.3 Turbo EP82 4E-FTE 12/89> 12/95
  • Toyota Starlet 1.3 Turbo EP91 4E-FTE 01/96> 12/99
  • Toyota Supra 2.0 Twin Turbo GA70 1G-GTE 02/86> 05/93
  • Toyota Supra 2.5 Twin Turbo JZA70 1JZ-GTE 08/90> 05/93
  • Toyota Supra 3.0 Turbo MA70 7M-GTE 01/89> 09/93
  • Toyota Supra 3.0 Twin Turbo JZA80 2JZ-GTE 05/93> 08/02
- Price is for 1 single spark plug