Truck Spark Plug Wire Change Interval

It used to be you would change plug wires by the third set of plugs or so. Is that still the case?
Im coming up on my 3rd set with 140K.

My ford doesn’t have plug wires, it’s coil on plug. On my other truck it doesn’t even have spark plugs.

suzuki wrote:

It used to be you would change plug wires by the third set of plugs or so. Is that still the case?
Im coming up on my 3rd set with 140K.

What do you drive? I’d imagine a lot has to do with the model and manufacturers recommendations.

Chev 1/2 ton. Ill do some internet searches too.

Spray them down with a hise and see if it runs like crap, if bot then i would let them ride.. I have seen them go bad as soon as 100k and i have seen them with 250k on the original wires.

time to change them if you have 140 K on them.
sure,I have seen many go longer than that but by that time mileage and performance has slipped away so subtly that you dont notice it until it sets a check engine light from a misfire.
as wires age the resistance in them goes up demanding more out of the coil when its triggered,the more resistance the more the spark tries to seek an easier path to ground.
when it does this the insulation of the wire breaks down allowing the voltage to find that closest point to ground.
often times its a bracket or bolt near by.
this will many times cause the coil to go bad as it heats up internally from the excess heat of the voltage collapse having no place to go.

several years ago wire change interval was recommended at 40K,personally to me it makes a difference on age more than miles,if they are over six years old,change them out due thermal cycling causing them to become brittle.
I would highly recommend that you buy as close to a factory set as you can,the cheap stuff will only cause more problems than they solve.
no need for fancy race quality stuff either that cost three times as much as factory.
the reason I say that it is most likely you are not going to replace the factory coil(s) with the super high voltage stuff.

Ordered some oem’s today. Will report.