sports cars cant use platinum spark plugs?
 

my mechanic told me that platinum ones are not good at heat resistance, he suggested me to change mine to copper ones, is it a good idea? cz i thought platinum are better...

:dunno: never hear that befor.maybe he did not have plamtium spark plup at that time, lol.

i actually had mine changed a few months ago, and they suggested to using platinum, told me they'll last longer, and today i went to another mechanic cz i had some rpm problems under extreme heat, and the mechanic, who self proposed that he used to work with hotrods, told me that under such extreme heat of high reving, platinum isnt good for the performance, so i was like wtf....

Despite what all the marketing may tell you, platinum is not for performance. It is used by OEM's often so that they can advertise "100,000" km's before tune ups since it provides long life. Copper provides far better electrical conductivity at the expense of shorter service life.

Long life + poor performance + = platinum
Short life + good performance = copper
long life + good performance = iridium (<-pretty expensive, though)

Personally, I just run coppers and change them every year.

Read this :

http://www.oqcgp.com/forum/kb.php?mode=article&k=50

Well, you might not want to use the same plugs as a Grand Prix is running, but the base of what you want to know is in there.

platinum will be fine for most any car on this site...

Use copper on a boosted engine.
Irridium if you want to spend the money for them.

Platinum plugs are not recommended in VR's either. They just cant' handle the heat.

platinum arneot good for type rs either

Platinum makes your car overheat if you drive too hard.

NGK/ OEM plugs are the way to go.

CO-SIGNED!

I'm using Iridium in my 04 Subaru STi, works great...

never, ever, use Platinum plugs in a performance car!!

I use copper on my boosted car. Ive read numerous times not to use platinum on boosted cars as the may break up under the extreme heat. Use copper and change them every year as said before.

I use copper on my boosted car. Ive read numerous times not to use platinum on boosted cars as the may break up under the extreme heat. Use copper and change them every year as said before.

I have never... heard that before. Interesting.

Just stick to what the manufacturer says. Even in my car stick with NGK coppers. they cheapest ones you can get. Alot of cars will be like that.

i use stock honda wires and plugs run sso smooth at idle havnt found aything yet that runs better.

The soundness of your advice depends on whether the car is stock or not. On a bone stock car, I agree in that you cant really go wrong with the OE recommendation. However, for a modified car, platinum is a poor choice even if that is what was spec'd out by the manufacturer. Btw, when I say modified, I dont mean a I/H/E. N20, boost or high compression often neccesitate the ue of copper/iridium plugs that are a couple of levels cooler.