When I worked at Champion and Autolite, we only put the threaded terminals on spark plugs that might be used for applications that needed them. So if an older car uses the same plug as a motorcycle, or something similar, it would have the threaded post. Especially for older applications, there wasn't enough demand for separate part numbers for threaded and solid post versions of the same part.
If we were making a spark plug for new vehicles, they would only have a solid post terminal. (At least if I was responsible for the design).
I would guess that the plugs for your Dodge have a threaded terminal, but the plugs for your Hyundai are a solid post.
Some new European cars still have a brass terminal nut, but those are usually mechanically locked onto the threads.
Speaking of spark plugs, I just got the newest Car & Driver, where they report on the long-term test of the Alfa Giulia. They had to pay $49 each for spark plugs at 30,000 miles, plus installation labor. This was just one of their complaints about the car. Someone (probably NGK) must have the only plug that will fit that engine.
I would imagine they are made for worldwide distribution where older cars may still be in use.
ReplyDeleteSome motorcycles use an ignition wire with a clip that holds onto the threaded post. The user just throws the nut away.
ReplyDeleteYes, but all car spark plugs have these screw on tips, why, is my question
DeleteWhen I worked at Champion and Autolite, we only put the threaded terminals on spark plugs that might be used for applications that needed them. So if an older car uses the same plug as a motorcycle, or something similar, it would have the threaded post. Especially for older applications, there wasn't enough demand for separate part numbers for threaded and solid post versions of the same part.
ReplyDeleteIf we were making a spark plug for new vehicles, they would only have a solid post terminal. (At least if I was responsible for the design).
I would guess that the plugs for your Dodge have a threaded terminal, but the plugs for your Hyundai are a solid post.
Some new European cars still have a brass terminal nut, but those are usually mechanically locked onto the threads.
Speaking of spark plugs, I just got the newest Car & Driver, where they report on the long-term test of the Alfa Giulia. They had to pay $49 each for spark plugs at 30,000 miles, plus installation labor. This was just one of their complaints about the car. Someone (probably NGK) must have the only plug that will fit that engine.
That's nuts! 50 a plug? crazy!
Delete