How Often Do You Replace Plugs?

[hypervish]

Originally Posted By: TFB1
Originally Posted By: SubyRoo
Be careful using a wire wheel on your plugs. When I raced go karts I was always checking the plugs to adjust the carb and a few times took a wire wheel to a plug and when I checked it the spark would be all over the plug not straight to the ground. Who knows I may have been too rough with the wheel.


Wire brushing can leave small metallic tracks on the porcelain, basically fouling the plug...

Originally Posted By: PZR2874
I use the 50% time theory no matter what the manufacturer recommends. Then again, I beat my cars up.


I basically do same... For the recommended 100K mi intervals, usually gas mileage will start to decrease after 60-65K mi...


Not for me, the gas mileage was just fine when I changed them. The only reason I changed them was because my uncle got the spark plugs for free, a $60 value. lol So, I figured I'd just install them, but the only catch was he needed the old one's back. It was for some research a company was collecting or something along those lines.

 

[Pop_Rivit]

I changed both the Hyundai and Subaru plugs last fall, first time for either car. Both cars have just over 100,000 miles on them and the plugs were original. There were no issues at all, it was simply time to do it.

I'm not sure if the plugs in my 1999 Dodge pickup have ever been changed, but unless I suspect an issue with one I'll never change them.

The plugs in the Subaru were noticeably worn. The Hyundai still looked good.

 

[MetalSlug]

I use copper plug so every 15k-30k miles, if platium I would leave in 50k+

 

[nleksan]

A while back I got a crazy deal on the factory BMW NGK BKR6EQP plugs as well as the same NGKs but with the proper temp range for my 328... I got them for $1.38 after rebate (each) so I have about 75 of the regular and 36 of the colder ones...

I change them anytime I have to take the plugs out (unless the current set have under 10k), and keep the set taken out in the box of the ones that went in after cleaning and regapping them. I write how many miles, gap out/regap, date, etc on the box so I know what they went through and so as not to waste 100k plugs with only 30k on them, for example.

With the 328, I went through a ton of plugs simply trying to get the temp range right and trying to get the tune just right. One set lasted all of 100mi due to running way too rich initially, and being a bit too cold. Experimentation...

 

[Ursae_Majoris]

Plugs in my Axiom are original factory double platinum NGK. FSM calls for 100K miles on them. I have 65K miles and 10 years on them and I've been debating whether to change them.
It is a waste spark system. Car is running fine. I am concerned about plugs seizing in the aluminum heads, though.

Changed copper plugs in my old Mitsu Mirage with 40K-ish miles on them. They needed it. Did not know better at the time and went with Bosch + 4. Car ran like a champ 2 years later when I sold it.

 

[artificialist]

Originally Posted By: Ursae_Majoris
Plugs in my Axiom are original factory double platinum NGK. FSM calls for 100K miles on them. I have 65K miles and 10 years on them and I've been debating whether to change them.
It is a waste spark system. Car is running fine. I am concerned about plugs seizing in the aluminum heads, though.

Changed copper plugs in my old Mitsu Mirage with 40K-ish miles on them. They needed it. Did not know better at the time and went with Bosch + 4. Car ran like a champ 2 years later when I sold it.


My father's 97 Lexus ES300 had similar plugs and ignition system. 60K was the manufacturer's interval, and 60K was all you could get from the.

I would change the plugs now.

 

[mechtech2]

Originally Posted By: MetalSlug
I use copper plug so every 15k-30k miles, if platium I would leave in 50k+


Then simply use copper platinum or copper iridium plugs.
Copper and precious metal plugs are not diametrically opposed - they can be integrated.

 

[ltslimjim]

I change the OE spark plugs on this VX every 30,000 as per the manual(2 years is another recommendation).

 

[subiedriver]

I just had new NGK Vpower plugs put in my Subie, after 26,000 miles. I've noticed a performance gain with the new plugs, its more responsive. I think after about 25K, the copper plugs performance deteriorates.

 

[heathenbrewing]

Originally Posted By: mpvue
if I'm going to bother taking them out, then I'm going to replace them.


This sums it up perfectly!

Coppers cost me less than $1.50 and I need 4 of 'em. I replace mine way too often (yearly) but the cost vs. piece of mind makes it a no-brainer for me. At that price, I couldnt be bothered cleaning 'em.

 

[CBR.worm]

With the infinitis I do it every 60K. I don't know what the manual calls for - I think 100K, but I drive both of mine like rentals.

 

[LazyPrizm]

I replaced mine at 100K, taking out the original Denso iridiums. I put in Bosch Fusion (?) IR, the ones w/ 4 side electrodes -- but now I'm reading that some people think the 2/4 electrodes aren't so good for mpg?

 

[cutter]

Originally Posted By: LazyPrizm
I replaced mine at 100K, taking out the original Denso iridiums. I put in Bosch Fusion (?) IR, the ones w/ 4 side electrodes -- but now I'm reading that some people think the 2/4 electrodes aren't so good for mpg?

Hah, I have done the same exact thing and we have pretty much the same motor. Got an 01 celica gt with a 1zz as well. I replaced the stock denso iridiums with Bosch Fusion IR, but at 80k at the end of December '11. MPG hasn't been as good as what I normally average in total on the Denso (year round), but then again, it's just been winter in which these Bosch plugs have been running.

 

[david_ES2]

My 04 comes with denso double platinums, i believe they are good till 110k, probably change them at 80k when i do my timing belt with some denso iridiums. Hopefully i can still find made in japan ones by then lol