Should I change spark plugs?

I have a 2004 Nissan Sentra, Looking to change spark plugs if needed, they been in the car at least 4 years and plugs have 44,000 miles on it. My car calls for double platinum spark plugs and these are single platinum. How important is it to not downgrade spark plugs because a guy from Autozone said the spark is the same from all plugs, just the plugs last longer and able to take more heat, no performance difference. Curious if this is wrong and could I upgrade to laser iridium? Or stick with double platinum what the car calls for? And is it ok to go with other brands like Bosch, OE is NGK plugs?

Looking at my plugs, how are they? There’s a little bit of white ash on the curve tip of plugs (I pulled the plugs out last 2 years and it had the white ash). The 3rd plug over has a little extra oil on it, even out of the plug hole on the porcelain (that wasn’t like that last 2 years) there no leak in the spark plug tube unless there a crack at the very bottom of it. Should I switch plug 2 and 3 and see if another plug gets oily? Why is that plug like that, not sparking good, the seal on the spark plug is not good, can the plug develop a crack and leak threw there that i can’t see?

Doesn’t that answer your question. If you are able to change them and you want to just go ahead and see what happens.

Almost always the best plugs are the ones specified by the carmaker. Anything else is an experiment; results may vary, but tend toward the downside.

I vote for putting in fresh OEM plugs. Although it doesn’t happen often, we do occasionally have reports here of odd problems when plugs other than OEM are used.


44K is short life on plugs. unleaded gas will allow good plugs in a good engine to run 100K easy. As for the design, better quality features are always a good thing. Go to iridium, it won’t hurt a thing. Use single or double platinum, if you want. They should be fine. I’d go with NGK or Denso plugs.

Why not Bosch? I really like Bosch plugs but they were NOT happy in my Honda. They worked well but kept trying to unscrew themselves. Odd. I never had that problem before in any other car. But I returned to factory-brand NGK’s and that problem went away.

Actually the plugs look very normal. A little oil on the thread and gaskets is normal. #1 and #3 might have been a tad loose or just got a bit of oil on them when installed then cooked a bit. The ceramics look good, no oil as do the electrode tips.

I’d put them back in ad check again in another 40,000 miles.

Double platinum matters in some cars (don’t know if that includes your car); for example, I have a car with a “waste spark” system where the spark goes both from the center electrode to the side and at certain times in reverse from the side to the center electrode. Double platinum matters for that engine, and that’s specified by the carmaker.
So if they are specified for your car, there’s no reason to mess around with it.

I would definitely check plug gap, yes they look good enough to use for more miles, but the gap difference between plugs throws a red flag in my observation.

You’ve got them out, why would you not put new ones in?


Some of us $36 possibly on new parts not needed is $36 wasted.

I’m one of those posters who had trouble when using something different than OEM spark plugs. Just don’t do it.

Having said that… since you’ve got these out already, I’d go on and just replace them with new OEM plugs. Move forward with life.

Good luck.