The car manual for my 2003 gt Elantra says use only iridium NGK plugs. When I changed the plugs and wires the old plugs were just standard copper core Champion plugs. My question has anyone else used the much cheaper plugs in their own Cali spec Elantra. Unless I'm missing something I think I payed 5x more for nothing.

Also
1 I have 2 catalytic converters so yes I do have a Cali spec.
2 I have noticed no increase in hp or mpg with the required NGK iridium plugs vs the old copper core ones.

What was the reason for changing your plugs? Were you having problems, or was this just some preventive maintenance.

Preventative, it was time to replace them. Bought the car with 52000 miles on it and now it has just under 82000. I have gone though two full tanks of gas since replacing the plugs and the tank average has not changed. So what is the risk if any to my engine if I just go with the cheap copper core plugs next time?

I am no expert on spark plugs, but I think it comes down to personal preference on this. I just changed my plugs, wires and pcv valve on Friday (18 July 08) due to a Check Engine Light and it was popping codes P0300, P0301 and P0304. Basically misfires. I used NGK 7962 Iridium's for my 2001 Elantra and there was an immediate and noticeable improvement... But I was having problems with the vehicle so this wasn't preventive maintenance.
I think any risk you may have on using cheaper plugs is that you may have to change them out around 12000-15000 miles (that's what I read in the forums anyway) On a good set of platinum's or iridium's, you can be looking at around 50,000 before a change may be needed.

You can find much info on this subject by searching this site, elantraxd.com, elantraclub and hyundaiforum.com. I hope this info helps! :)

This post has been edited by yoakumk: Jul 20 2008, 03:23 PM

I know that the cheaper copper core plugs need replacement sooner. The reason I posted was the car manual said I have to use the NGK Iridium plugs. From what I found on my own. The platinum and iridium plugs produce a lower temp spark. Is this low temperature spark just advertising or is there something to it?