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Spark Plug Variations

It seems there are just as many spark plug types as there are car manufacturers. I’m thinking of doing a tune up on my car soon (before the weather around here gets too cold) however I’m at a stalemate when it comes to choosing the right plugs and/or wires. I hear that the Bosch +4 tipped ones work well at first but degrade significantly over time, thus not being a very good choice. My questions are: Will new plugs and wires restore my car (which has been VERY well maintained) to a smoother idle and better performance? Is there a major difference in plugs? Is any one plug better than the other? If so, what would be your main choice in plugs and wires. I currently drive a 2002 accord 4-cyl. There seems to be little unbiased information on the web regarding this. Thank you all very much, and I appreciate your input!


Buy the exact brand and model plug that is specified for your car. Next to nothing to be gained by changing, and sometimes your car will run worse. Ignore the ads.

I believe the best plug is the one the mfg put in the motor in the first place. You can get the plug info in the owner’s manual. Honda uses NGK, or Denso plugs which come from the same factory. Mostly a set of new plugs really shouldn’t make a big difference in performance. The idea with pollution controls is to replace the plugs before they cause a running problem. Therefore unless you are way overdue for new plugs, don’t expect a change in idle, etc. You may have another problem with the car.

The Bosch plugs you mentioned haven’t done very well, pass on them for sure.

Salesmen and women sell brand name plugs to auto manufacturers. The size of the plug has more to do with the engineers specs than the brand does. There are handy cross references for plugs at the parts store, and the price points dont vary very much. The major brands are all pretty much the same, since they all have to meet the industry standards. The four points plugs are mostly a gimick to try to grag market share. Fall for it if you want to. New plugs are generally better at burning oil than damaged used plugs that are all carboned up. So if you are burning oil, they can help give you cleaner burning for a while.

I buy my spark plugs for my 1998 Civic from the dealership. They are a little more expensive, but it makes my life a little easier to know I have the right ones that are properly gapped.

Replacing the plugs and wires might make it run smoother and it might not. We can’t know for sure until you try it. If it is running rough, it might not be because of the plugs or the wires. However, doing this tune-up would be a good place to start as far as ruling out some factors. If it doesn’t fix the problem, I would then consider replacing the distributor cap, cleaning the throttle assembly, and checking/replacing the PCV valve.

Thank you all very much. Honestly, I figured that putting the exact plug would be the best, the reason I brought this up is because my friend feels that the bosch plugs are best and is currently going to install them in his jeep. He is one to easily fall for ads and tricky marketing techniques. Thank you all very much for the input!

Your thinking is correct. Exact replacements are the best approach. For a Honda I’d recommend the NGK brand. That’s one of their OEM suppliers, and the listed replacement can safely be considered to be exact.

Note that sometimes even the NGK catalog (for example) will list more than one OEM replacement part number. In this case ask the parts guy to show you on the screen exactly what the differences are. In my car, there’s actually a few slight variations of the center electrode that are all considered OEM replacements. One is cnsidered an improvement over the other. “Reading” these codes will be an interesting education for you.

When I was growing up, cars weren’t so fussy. We had a 1952 Dodge 6 and a 1954 Buick. The Champion J-8 spark plug would fit both cars as well as the 2 cycle LawnBoy mower and the 4 stroke Briggs and Stratton on the roto-tiller. I didn’t feel any engine was worth having if it wouldn’t run on a Champion J-8 spark plug.

However, times have changed and I think you should use the make and type of spark plug recommended by Honda.

“my friend feels that the bosch plugs are best”

True, if that’s what his Jeep originally came with.