Basic Q but...

[Tony.]

How often do the spark plugs and leads need to be changed??

I have had the car since 47xxxkms and it is now about 89xxxkms and as far as I can tell (ie service invoices) neither of the above mentioned have been changed.

If they are up for replacing, what am I looking at for replacing them price-wise? (GMH and/or aftermarket?)

[235rwkw]

What motor V8 or V6?

[fitz_vt]

What motor V8 or V6?

yeah it depends
spark plugs are generally around 4.50-6 dollars each, they should be changed at somwhat regular intervals (somwhere between 10000-20000K

[pablo]

The 'good book' calls for a change at 40,000 K's. Mine have been in for over 47,000 K's, only because I think that perfectly good plugs are thrown out unnecessarily. My leads 'packed up' around the 160,000K mark.
Just do what makes you happy.

[fitz_vt]

The 'good book' calls for a change at 40,000 K's. Mine have been in for over 47,000 K's, only because I think that perfectly good plugs are thrown out unnecessarily. My leads 'packed up' around the 160,000K mark.
Just do what makes you happy.

yeah i have stock leads in a 1997 corolla that have lasted 238000k's
and spark plugs that hadnt been changed since the 150,000 service (about 60,000) and then got told off by the mechanic for not changing them earlier