I'm not really sure about which spark plugs to put in my car wether to go with the colder plugs or some iridiums. My engine has a higher compression than the stock 9:1. thanks for your imput.

 

Stock compression is 10.0:1... Anyways if you are NA you don't want to put colder plugs in there, nor would Iridiums provide any benefit. Stick with the NGK Coppers.

 

But he has an 89 Max... Do they still have 10:1?

 

yup 10char

 

no it's 9:1 stock I have Z rods and pistons which are 10.5:1 on a 4 valves/cylinder head and mine are 2/cylinder. so the compression might be a bit higher. so my combustion chamber is smaller that that 4/C heads.

 

I was talking about VQs being 10:1. I didn't know you had a VG. Regardless, the part of my post about the spark plug remains the same