The local Mazda dealer says no plugs or coil need be changed at 30 k. The 09 rx8 is running fine and I can use the savings. I had read somewhere that spark plugs and coil should be replaced at the 30k.

What is correct?

 

Inspect your spark plugs and see for yourself...
That's the best possible advice

 

If u want top perfornance, then yes.

Otherwise. No and inspect then every 5k miles

 

I believe the owner's manual says to replace the plugs at 36k. Service guys not familiar with the RX-8 tend to not believe that because the interval for most other cars is 60k to 70k.

There's no specified replacement interval for coils, but they can fail after about 30k to 40k. Kind of like timing belts, where some car makers don't list a replacement but after 60k anything can happen.

Ken

 

It's different for everybody...My last plugs went to hell in 3 months (9k miles)...I've also had 2 coils go bad in 2k miles...that was before I switched to bhr.

 

Likewise, You have to check as it's different for everyone. As I recall, my plugs were changed at around 88,000 with the cat-converter; I passed 100,000 miles with original factory wires and coils but had to have all (plugs, coils, and wires) replaced at 141,000 miles(52,000/22 months). Then it was after 10,200 miles/19 months and 8,300 miles/3 months, respectively, that the plugs were replaced. I now have close to 5,000 miles in my current set of plugs.

 

I bought my car with 37k miles on it, and changed the plugs right away... They should've been changed about 7k earlier. My coils failed at 39k.

So yes, I would change the plugs at 30k. Personally, I would wait for failure to change the coils. HOWEVER... If you aren't able to recognize the symptoms immediately, you can cause serious damage to other components by driving around with a misfire.

 

I am the second owner. The first had kept records of all the receipt from mantenance and repairs made at the dealership and that was the only time the spark plugs, regarding the ignition system, were replaced. Surprisingly, it was shown that he had it replaced free of charge.

 

oMazda replaced my plugs once or twice under warranty. No biggie, soon mazda will not have to replace them for free anymore

 

Sometimes, it could be less than 30k, or it could be more than 30k, it depends on the situation of the car is in. Anyway, follow the owner's manual on scheduled and preventive maintenance, read the stickies, and follow the procedures on how to take care of it seriously. Good luck.

 

I was referring to the Catalytic Converter(@88,000 miles), as well.

 

they replaced mine too. once. Cuz the original one was "gone", meaning completely burnt. hhahaha when it was clogging the engine the car can barely go up my driveway ... lol

 

I ran mine until a coil went up and got a misfire. Lasted to 53k. Did coils and plugs now at 72k still rolling strong.