Who is the rx8 Club Forum resident spark plug reading guru? I have a set in need of reading.

Front Rotor 40k Miles


Rear Rotor 40k Miles

 

Look fine but due for a change. 40k is a bit too long for plugs. Not bad at all considering.

 

whats the typical lifetime for the spark plugs? Asking for a friend

 

After 30k everything ignition related is suspect. Coils, spark plugs. I inspect my spark plugs every year, and replaced every 2-3, at 8000mi per year.

It's not that they're finished at that mileage, it's that when ignition starts to go on these cars, the first symptom is often engine failure. So you want to treat it preventatively.

 

Those look fine and reflect a relatively healthy system.

I'm going to disagree with Loki on one point: everything in the ignition system is suspect at 20K miles. I had a factory Rev B coil fail at 10K miles. That spooked me into going with the BHR upgrade. Now, I don't worry about coils or wires, but I do check the plugs yearly and replace them every 20K miles.

 

Why do the wires not wear out? I could understand the coils not needing replacement, but aren't the wires the same as any other set?

 

Wires don't suuuuper wear out at all, but being where they are, low to the ground, they can be damaged or the contact points can oxydize. Good idea to inspect when changing plugs, not necessary replace.

 

Thank you, Loki and Steve Dallas.

 

Do you premix? These look okay for 40k miles.

As for wires, you could always inspect their resistance with a multimeter. IIRC the OEM wires are also made a bit differently from most aftermarket wires. OEM wires wear out a bit faster.

 

Not pre-mixing as of yet. Need a mid-pipe and Sohn. Wires are coming with new coils.

 

I just noticed both pictures are the same picture. Doh!

 

Correct photo of front plugs Good catch Loki...