In article >,
RV > wrote:

> On Fri, 10 Jun 2005 21:52:48 -0400, "RoB"
> > wrote:
>
> >I am looking at replacing my spark plugs in a 3.8l GM engine (high mileage)
> >and was looking at those NGK G-Power Plugs but a friend of mine says just
> >put the cheapy AC Delco, because the platinum won't make any difference
> >except possible quicker starts, but not worth the money... Is there any
> >performance difference between copper plugs and platinum?
> >Any suggestions would be appreciated..
> >
>
> You either have a combustion chamber configuration or compression
> ratio suitable for platinum plugs, or you don't.
> If you dont then dont run plat plugs.
> If the car manufactuers says run plat plugs, then you do have the CC
> for it and should run them.

Absolute rubbish. Neither compression ratio or combustion
chamber design dictate whether platinum spark plugs should be
used.
Platinum plugs are strictly a maintenance sell.

> If you need to run plat plugs it is for longer life requirments of the
> engine ignition maker, if you dont run them copper plugs will wear too
> quickly sending the ignition out of normal KV working range.

Actually, miss-firing occurs much before KV limits are reached,
miss-fires being a big no-no as far as emissions are concerned.

> If you dont have the CC for plat plugs and run them, they will more
> likely partially fail, possibly poor idle, unless, you are running a
> higher compression ratio as in racing, then plat plugs are suitable,
> if not desirable.

Racing would be about the worst place to run a platinum spark
plug.

> So its CC config (valve postion) or CR fuel that determines if you use
> plat plugs.

Malarky.

> If you have the CC that is configured the clean the plug tips, then
> use them., if you have heaps of CR then the heat will keep them clean
> enough such as with racing.

Double malarky.

> If you dont have the CR for them, or dont have the CC for them to keep
> the plat plugs clean, they will most likely fouled or as we say for
> plat plugs, contaminated.

We?

> If you have the CC config for plat plugs they are good to go at all
> engine temps as in standard cars that use them, if you have big CR as
> in racing, then you may need to use coppers to warm the engine, then
> swap to plats, or you may have trouble starting and dirty a new set of
> plats starting it.

Who invents this crap?

> Hope that helps.

I don't think it did...