Are spark plugs all the same?

[ihookem]

I think I need new plugs in my 08 Impala. Some are $15 , some are $5. Has anyone noticed the expensive ones are better and last longer?

 

[bcjoe]

They have different designs for better spark, whether that is true of not is up for debate. There is one important thing to remember is that they have different temp ranges which is what the single digit stands for on the model of plug. For instance a 5 is better for colder weather and a 6 is better for warmer weather or condition. I would stick with what whatever the OEM recommends and gap those plugs according to OEM. That is how the engine was engineered with trial and error, just my 2 cents.

 

[hoooogan]

Short answer: Just use OEM plugs. You have a better chance of losing performance if you switch away from the OEM iridium plugs.