Replaced OEM spark plugs @ 106k miles

had the dealer replace the spark plugs on my 2014 4runner (bought dec-2013).

only used 87 octane w/ ethanol for 106k miles and 10.5 years.

here are the plugs (not in order of cylinder).

edit : added stat pics at end


edit:
weekly commute was roughly 25 miles round trip daily for 5 days week for 18 years (1998 to feb-2017)

then my weekly commute was 25 miles week round trip daily for 4 days week for the last 7 years (feb-2017 to present)

once the work week was done, it was parked in the garage until monday morning. if when i did go out, i usually took the wife's 2016 tacoma, 2018 tundra or 2023 tundra since we barely put any miles on it (her 2018 had 43k miles when we traded it on our 2023 tundra which only has 7800 miles after 18 months)

 

Wow, doesn’t look to bad for 100K

 

the buildup on the 5th plug was iffy. i am going on a 4k trip to see my mom in september so i didnt want to get any ignition issues on the trip.

 

Those plugs were surprisingly clean, compared to US vehicles.

Did you replace your plug wires? I've had some disintegrate at around 150K miles.

 

no i didnt. wasnt advised by the tech to replaced them. was told $200 per plug.

 

It is a US vehicle, the OP is in N Dakota?

 

i mostly wanted to show what using 87 octane with ethanol would do to plugs for 10yrs and 106k miles.

i never used anything but 87+eth gas during its whole life as i never saw the need to use anything higher ($$$) once.

did oil maintenance every 10k then switched to 5k at 90k miles.

all the following was done in the last 20k miles and everything was oem until recently replaced

brakes and rotors @ 98k miles ($500 per axle) (was told brake fluid was still oem spec) had the fronts done before i went on my sept trip to GA and the rears done when i got back (they had 2mm left on them when replaced pads)

spark plugs @ 106k miles ($365)

coolant chemical clean refill @ 90/95k miles
accessory belt @ 90/95k miles
all 3 diffs @ 90k or 95k miles (cant remember, it was a while ago since i dont put many miles on it anymore 2022/2023)
all 3 above where done for just under $600-$700

oem oil pressure sensor cracked at 103k miles, replaced for like $120-$150 (labor was the most as it took a while to clean up the engine bay. the tech did a great job cleaning up the engine bay of oil ( i went and looked afterwards from above and below)

 

Put em back. Good for another 20K at least.

 

for $365 out the door, yeah not going to happen

and i have a 4k round trip to ga this sept.

 

What App is this that you are using for the stats? TY

 

What "plug wires"? These things haven't had distributors and wires since the 2nd or 3rd gen AFAIK... Do you mean replacing the coils? There should not be a need to unless one fails.

I'm curious - what did you expect it to do?

 

Those plugs could have gone another 50,000 without breaking a sweat, honestly most people these days dont think of plugs as preventative maintenance and just keep driving. Its not uncommon to see vehicles come in with
"i gotta slight miss every now and then it just stumbles like at a red light"
with 220,000 miles on it and stock plugs. Typically this is when the electrode is almost gone and the plug gap is well over .100" and there is a misfire every now and again and the ECU picks it up and does whacky stuff which is why you feel the weird stumbles as the ECU changes timing maps and fueling almost instantly.

I have seen them still look good with 180,000 miles on them before, but typically once you get around 200,000 they are pretty well shot.

 

acar that was eventually bought out by fuelly. great app before fuelly bought them, now its a monthly/yearly cost instead of a 1 time, they even retro'd the lifetimes into a month/yearly fee

im just too far invested into it now to switch. i have history in the app back to my 2010 legacy 3.6R

 

i thought the ethanol would have done more corrosive/buildup damage than it was

 

i just went with what ADM @ CCN suggested which was about ~120k before replacements.

 

Nothing to worry about in that case, the ethanol is not corrosive to the iridium core of the plug. It also shouldnt cause buildup, rather the opposite as ethanol is a mild solvent and has a slight cleaning effect.

The problems that people fear from ethanol comes when it attracts water, but I think that is only really serious issue in boats and ultra humid climates.

 

You definitely got your money's worth out of those spark plugs.

 

usually a tank only lasts about 10 days on average for either me (4R) or the wife's tundra. biggest issue we use to have is extreme temp swings during winter. going from anywhere from -20F to operating temp on the exhaust system (mufflers rotting out due to short trips) or not doing enough remote starts in the winter time to burn thru the gas and and moisture in the muffler/tanks from said temp swings.

dont use HEET as much as we use to in the winter time (maybe 1-2 times a winter, but havent used it the last 5-7 years)

 

The pads look worn on the side electrodes. Not abnormally so for the miles, but I've seen better from same mileage plugs from more "refined" engines. Most of the time I didn't like discarding "good" plugs at 100k+, but did so for preventive reasons. These shown I'd feel good about replacing.