100,000 mile spark plug change interval - fact or fiction?

[Wayne02]

My GMC claims to have a 100,000 mile spark plug service interval. Anybody let their plugs go 100,000 miles before changing? If so, how did the old ones look? Did you notice any performance difference with the new plugs?

 

[gunsmith11]

97 ford F150, changed the plugs at 160,00 because I was starting too feel guilty, truck was running fine, left bank still had a lot of miles, right bank electrodes were down to a nubbin, new plugs did not change perfornace, but the right bank did not have far to go....truck now has 205,000

 

[diamonback68]

Fact!
Don't waste your money changing them earlier.

 

[elcruisr]

Just changed 'em on my For Ranger at 100,000. They were indeed well worn but the engine was still running fine.

 

[Landpimp]

2000 Land Cruiser, plugs good to 120K, I replaced at 125K, plugs will looked good

 

[Jerry in SC]

Changed mine at 125K (2003 Toyota Camry now with 215K).

 

[walter o]

100,000

Yes ,100,000 miles on the new car spark plugs. Actually went to a dealer to have the 99 f-150 tuned up at 80,000, he changed the fuel filters and a few other things and told me the plugs were good (didn't change)At 100,000 + went to a different shop , had another problem and he did change the plugs . He said that at@100,000miles the coils may start to break down if the plugs are going bad. had them changed, good to go another 100,000 miles **##// the cash for clunkers deal

 

[cass]

I'm "old school". They're not that expensive, so I change them yearly. Same goes for oil/filter changes.

 

[michael thornton]

well i have 189,000 on my truck with the same plugs that it came with, still gets about 20 mpg like it did new,i think the plug wires go bad before the plugs do, mike

 

[diamonback68]

I'm "old school". They're not that expensive, so I change them yearly.

It's your money, but you are wasting it and gaining nothing.

 

[Landpimp]

the 8 plugs for my 2000 Cruiser at my cost were $70, I'd feel bad tossing that much away every year

now on my old Cruisers, I change them.....well when I think they need it.....I keep all tune up parts in stock at my house.

even got points on my 64 still.....gap them with a matchbook

 

[walnutred]

I changed the plugs on the Ranger and Expedition at 120K, the Suzuki just hit 100K and I'm beginning to think about changing them.

 

[ecam8000]

I get to pay the bills on a sales fleet. Some of the aluminium headed cars have been known to take the threads out with the high mileage plugs. That takes an easy job and makes it harder ($$$). Yes, in cast iron they may come out after 100K. But plugs do get higher resistance as they get older, coils and wires have to work harder for a spark. For my money (and the company's) I change the plugs early. I do skip the plug change on my diesels.

 

[Andy Griffith]

I agree that on certain vehicles, especially with designs of engines that are based on British or old Buick designs, the plugs do actually have to be changed often, but the wires more often than the plugs!

Usually in the 40-50K range, a set of wires are due.

I do have brand new set of 1940's A-25 Champion plugs that I found in the back of our local hardware store...I paid 10[FONT=&quot]¢ each for them a few years ago, which must have been the original price. Of course, these are meant for Model A's or for old tractors, generators or anything with a Model A style motor. But I've never had to change the plugs.
[/FONT]

 

[Spotteddog]

Yes (verified) they will go 100K.
When I did it (mid 80's) it was on a single unit in a police fleet. Even though these were early OBD still running carburetor's (84' Chevy Impala 350 CID 4bbl.), and W/O any exotic plug electrode materials. These were pre-individual coils and still running 8MM wires. IIRC the example car had 116K on it, before losing a plug. I had trouble buying in too, coming from a 60's high performance background. Now, with FAR more sophisticated engine control systems, improved electronics, and unknown "back in the day" spark plug materials, barring an engine getting coolant or oil in the wrong place, yes I'd sign on to the concept.
My only caveat would be, were I intending to keep one 100K+, and it ran aluminum heads? I might invest in a set of new plugs at the 2-3 year mark, this would only be so I could get some anti-seize on to the threads in the head? Hell! If they looked good at that time and I hadn't boogered up a plug getting it out, I might just re-install it after the anti-seize went on.

 

[m657]

....got 64K on a 2005 Hemi Ram....no sign it needs 'em yet.....

My first venture into the idea....plugs lasting longer than the old VALVES used to!!!! The idea!!! The last new car I bought was a 69 beetle....despite meticulous care & attention, burnt valves @ 43K.

 

[Spotteddog]

The marvels of pre-Stellite 77's valves, on an air cooled!
Its why H-D's used to need a freshening up on the heads once every 2 seasons. Iron head Sportsters or aluminum big twin shovel's, same/same.
I recall guys running Sodium filled exhaust valves on the Beetle's, but even that did nothing to help the seats?

 

[Senior Citizen]

My GMC claims to have a 100,000 mile spark plug service interval. Anybody let their plugs go 100,000 miles before changing? If so, how did the old ones look? Did you notice any performance difference with the new plugs?

XXXXXXXX

Bought a Pontiac GP in 1992 for teh wife. Traded it in 2005 for an Impala. GP had 114K on it when I traded it in. Got the same 29mpg day after day. 2005 Impala has 84K on it and feels just as fresh as the day I bought it.

I have no idea what brand of plugs were/are in them though. All I ever did to the GP was replace the battery once in 13 years and put a new altenator on it. Change oil every 5K too. That's all.

 

[Ailog]

gunsmith11 "97 ford F150, changed the plugs at 160,000"

I have a '97 Tbird with the 4.6L engine. Changed mine at 130,000. Ford used platinum plugs which is why they last so long.

 

[scottaschultz]

1999 Jeep Cherokee with 237,000 miles - 2nd set of spark plugs and 3rd set of tires (Uniroyal Laredo)

Scott