How long have you gone one factory set of spark plugs?

2nd gen here, but I'm currently at either 58.5k, or 88.5k depending on if the original owner did them at 30k or not. I meant to do them at 60k, but never got around to it. Plan on doing them at 90k for sure though!

 

I don't remember where I read about the plugs, but to keep your emissions warranty, you need to change the plugs at 60K. Modern iridium type plugs can probably go way longer in our trucks, but changing early ensures efficient operation (more complete burning of the fuel which can foul emissions equipment).

I had a 2002 S10 that didn't get plugs changed until 100k. It ran fine the whole time. Don't use cheap plugs or wires as they will last 30k maybe.


Edit: oh, I changed mine at 60k. They still looked good.

 

I would surmise he's never changed plugs on a Subaru. Pulling the engine is probably easier lol. Made me miss changing plugs in my Jeep's 3.7L V6.

 

Changed mine at 62k. Couldn’t really tell the difference in performance or throttle response, but I did see a small gain (.5) in mpg.


Edit: Hey OP, third gen recommended is 60k.

 

Still on originals at 52K ~ 5 years, will change at 60K, which will probably be in a year or two. Maybe change them sooner if I'm bored.

 

Just changed the originals out of my 2007 at 32,500 miles... had been in there for 14 years.

 

In my 60 years I have never ever noticed an improvement in starting/running/mileage after changing spark plugs as maintenance. I've had plugs that would fire when cold then, not when hot, some that had the porcelain cracked and some that were fouled and then, there was a difference after replacing. I've seen plugs with~120k miles that had the electrode severely worn and still ran fine.

 

And the guy that lost compression on a cyclinder because the electrode burnt off (while it was running good past 60k) and fell between the rings and wall will never say, saving a few bucks and not changing his plugs was a good idea. IMO Toyota did not say 60k plug change to sell more plugs. These modern plugs dont look nothing like the 1st plug I changed in 1979 with a huge tip and melted down on 1 side like it touch the sun. These new plug tips are less than .5mm. Thats insane, and what the hell is irdium?

 

For me it was a bit of if it ain't broke don't fix it plus procrastination saying I'd do it next oil change to tackle it all at once and never getting around to it. But I got to say the OEM ones were quality stuff to last that long.

 

I drove my 4cyl 2004 on original spark plugs for 165k miles. CEL came on, I changed them and kept going......

I changed my 2017 3.5l iridium plugs at 70k, they could have gone to 100k, easy.

 

My truck just turned 100k and I’m still on factory plugs. I’ll be changing them out soon, since my gas mileage is seeing a slight hit now. Getting 20-30 miles less mileage per tank of gas.

 

Wait. You can change the spark plugs?

 

Back in my younger days, we would swap out plugs just to have something to do on a lazy summer day. After a year or two of use in those old carburetor engines with distributor cap timing, they could look pretty rough! But these days, with computer controlled electronic ignition, these plugs damn near last forever! I mean look at some of the pics being posted in this tread of plugs with 60K miles or more that look almost new!

 

Thank you for the photo

 

Wanna bet they never did them? lol. Time for some new plugs.

I was also pretty amazed at how long people are stretching plugs in this thread. Not a smart move.

 

2.5 Gen, just bought this truck. I did a complete fluid change (aside from brake and power steering) and tune up at 37,000 miles. Changed the OEM plugs with Irridium.

 

80 k is the expected life unless you have a symptom of early failure. I’m prepared to defend my comments but my passion for the topic has already waned.

 

Yeah it was always the one job that would take *just* the amount of work required to get passed over (not to say its hard though). It's also one of those things that doesn't warrant your daily attention like used up brakes or bare tires would (until the plug fails at least ). Having a garage now is also a huge blessing. Used to only have a parking spot to do all my maintenance in.

Are there any indications the spark plugs are going bad that you can hear/feel, or is the only way taking one out and looking?

 

I changed mine at 150k. Still ran like new.

 

The plug chug. Lots of indicators. Drop in fuel economy. Hard starts. But usually beyond a certain time frame if you don't notice anything, you will notice the knock. Sometimes only under hard acceleration until it gets real bad then it's just gonna misfire all the time.