Is sparkplug life span measured in time only or by mileage? My truck is nine years old but has only 80,000 miles on spark iridium plug. Is there a good reason to change them up before GM's 100,000 suggested interval?
It’s more mileage. You have to understand that you have iridium plugs. Iridium is a rare metal and the reason to use iridium is because it breaks down less over time inside your engine, instead of driving and having sparks explode. It’s bad enough that the spark is exploding with hundreds of thousands of volts that can eat some of the metal but of course there’s gasoline burning and a little oil gets inside and burns. You really have to have something that’s strong. The iridium is very, very strong.
I have had GM trucks, and I’ve had a customer with 200,000 miles on it and the spark plugs were still good (the original iridium plugs). So, I wouldn’t change them now if I were you. If you are not burning any oil or anything, it should be perfectly fine. When it’s time to replace your spark plugs, you can enlist the help a certified mechanic, such as one from YourMechanic to perform this service for you promptly.
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