^ different for everyone depending on how the vehicle is maintained, how driven, fuel quality, etc.

The only way to really tell is to pull them and take a look. There shouldn't be too much black soot (although most 8's run very rich). Ideally a brownish-tan residue).

Having said that, 12k miles is a good rule of thumb.

 

its debateable. I would change them every 12k to 15k miles. Depending on their condition, it is cheaper to just clean them. Cleaning them is not my expertise so, you would have to ask others that are more familiar with the process and what all to do/look for.

 

went to take out my plugs past monday. my friend and i were having trouble getting the first plug out, any recommendations? read torque wrench and breaker bar in this thread, are those the only solutions

 

Make sure you're using a 13/16" spark plug socket (not a regular socket).
If its tough to loosen, someone may not have used anti-seize on it last time, so make sure you do when you install your plugs.
Don't use a torque wrench to remove the plugs.
You can use a breaker bar, but it shouldn't require THAT much to loosen the plugs... maybe go work out at the gym

 

yeah i purchased a 13/16" spark plug socket from autozone, ill prob take a breaker bar to the damn thing see how that goes.

 

Was in for an oil change today and just out of curiosity asked how much just to install the plugs I bought (haven't had time to do it myself yet)

$150!... Just for the install I don't get where they came up with that number. Should just be paying for labor which should take maybe 15 min tops for a pro. If it was maybe $25 I would have said go ahead...but geez...$150!?

 

i like to call that the "dont ask us to do this" fee. they either didnt feel comfortable doing it, or had never changed the plugs on a rotary before.. so they're basically throwing out a number they know most people will say no thank you to.

 

i am changing them every 30k miles, works fine so far XD

 

Well, I am close to 90k, so it's about time for that maintenance stuff. I just wanted the oil changed but they seemed pissed I wouldn't let them do the tranny fluid and the other stuff. Thanks to the DIYs on here I am very comfortable doing it on my own and Im not even very mehcanically inclined. Planning on doing the plugs next weekend and Im gonna order some coils this week and do that too. If stealerships wouldn't charge so damn much I'd actually let them do the work, but the prices are just getting out of hand for this stuff. It actually makes me feel really good that I have learned to do all of this stuff on my own. I actually enjoy doing it.

 

Hey Fellas. I just changed the spark plugs on my car with 40K on the odometer. Boy what a difference it makes. The car idles much smoother and runs like it's supposed to. Anyone waiting to see if they need to change their spark plugs can look at how mine were .

Funny how I always take my car to the dealer for routine maintenance and they never mentioned new plugs. I have new coils and wires on the way.

Thanks for the useful info from everyone. I freakin' love this forum!

 

I should have read this thread before changing my plugs, as I now realize that I over torqued my plugs

If I torqued my plugs to 25 ft-lbs will I be ok ?

 

great thread, any opinions on the best place to get coils/wires?

 

BHR has a coil package you can't go wrong with.

 

while you brought it up. i know there are hundreds of pages of stuff one the BHR ignition kit but is it worth the money??? what are the main benefits? cause its alot of greet

 

The main benefits are stonger coils that will out last the oem coils that are known to fail, and they make it harder to flood your car.

 

I'm looking at these
http://www.okadaprojects.com/usa/products_direct.htm

 

I think you'd be better off with BHR. My guess (not knowing anything about them,) is those plasma coils are more gimmick than real performance. Probably not as good as stock.

 

"Plasma"...HOT COILS..our coils get Hot enough as it is....Sounds like a load of BS to me, especially the price!...ridiculous

 

$735 for a set of coils?

 

I changed my plugs today after reading through this thread a few times. All 4 were easily accessible by removing the drivers wheel, I never had to get under the car. Start to finish was about an hour, and I really didn't try to rush. Thanks for the info here, made the job a piece of cake.

 

Thanks OP. Your thread made this a 20 minute job!

 

I f any of ya are looking for factory ngk plugs theres guy on ebay selling them for good price not sure how many sets are left i just recieved set from him
way cheaper than the dealer with free shipping , stock ngk plugs worked great new ,

 

Thanks so much for the info, tomorrow, I will be changing mines, wish me luck!! :D

 

I did it!!!! It only cost $85.49 for everything, the four of them were fried literally lol! It sux how Mazda wants to rip off people ..

(Yeah I can work on cars and no, im not affraid of the grease)

 

I envy your hubby.