wimpieguy

I am trying to order some greddy iridium spark plugs and dont know what type to order. As well as different heat ranges they come in two types, ISO and JIS.

This is what it says;
** ISO (International Standards Organization) - The ISO height for a spark plug from the seat to the top of the terminal nut is 50.5mm

*** JIS (Japanese Industrial Standard) - The JIS height for a spark plug from the seat to the top of the terminal nut is 53mm

Does anyone know whether i need ISO or JIS please?

Thanks

wimpieguy

Does nobody know?

Jolly Green Monster

iTrader: (4)

I would stick with the tried and tested NGK plugs..

wimpieguy

Greddy plugs are made by NGK.

myblackwrx

iTrader: (1)

JIS is the 'Japanese Industrial Standard' and specifies the height of the spark plug from the gasket or tapered seat of the sparkplug to the top of the terminal nut (or threaded terminal) as 53mm. ISO is the 'International Standards Organisation' standard for spark plug height and is 2.5mm shorter than the JIS standard at 50.5mm. While the small difference in height will not affect most vehicles (ISO and JIS types can often be interchanged), some vehicles (particularly with direct fire ignition or specially fitted plug caps) MUST use the correct plug standard or a bad contact between plug and cap may be result. See diagram Common ISO type plugs are NGK BKR, Denso K or IK and Champion C or RC. Common JIS types are NGK BCP, Denso Q or IQ.

Taken from here

Spark plugs FAQ

Slowboy Racing

So just go with NGK, it will probably be more straight forward

wimpieguy

Thanks for responses everyone.

Myblackwrx, hope you are doing ok and thanks for digging the information for me.

myblackwrx

iTrader: (1)

I'm fine thanks and always willing to help