Spark Plugs
 

So the other day I was going to change the plugs in my Alero and when I took the plugs out they weren't the factory plugs. They were a E3 diamond fire plug. I've heard of these before and how they are "suppose" to help you get better gas mileage. The previous owner put these in. Was wondering what other people knew or thought about these. Should I leave them in or get different plugs. If i should get different ones, which ones should I get?

Um here's a half arse answer... If it makes you feel better than do it. Everyone loves new plugs (unless you buy bosch and then you cry). most new plugs seem to feel better. There's lots of posts on this and I can sum them ALL up in 3 sentances. 1) ALL PLUGS ARE THE SAME 2)MY HI TECH PLUGS ROCK! 3)I BOUGHT BOSCH PLUGS AND MY CAR IS MISFIRRING! (this comes with 1, 2 or with a HELP tag!.)
That's basically what I've gathered from the posts. I think it totally depends on the plug and the engine. it's one of those things that will either be better or just as good...

if its not miss firing then leave them. if you really want to replace them anyways get ac delco. get the platinums if you are feeling froggy.

how many miles are on your spark plugs?

no not all bosch is bad.. only those freaky ones that promise higher performance. the plain jane boschs work great for us... its the only plugs we typically use at our shop.

Bosch is usually pretty good. For plugs I personally just go with NGK Iridiums. They're not that pricey either... I think around $10/plug vs $5/plug for the cheapos.

i better change mine, i think they are still stock but i haven had them changed since i got my car and thats over 50,000km ago

ngk are better suited in forgein cars

agreed, and if you want a bit better go with the NGK Platinum Iridiums. about $15-$16 a plug (the ones I got in my car)

plugs
 

Ive always gone with plugs made by the man. Its usually one less thing to worry about. The regular ones not IR/PT or $$.

I had an interesting thing happen when trying "rapid Fire" GM plugs in an old 2.8. The car started to miss occasionally and the last thing I suspected was the plugs for they were new.

There was one plug which had the insulation crack and slide down the electrode like a turtleneck. It taught me to always suspect the plugs as they are in a pretty high wear place and can fail.

The ACDelco Iridium plugs for the 3400 (part number 41-101) are made by NGK.