My 2009 has 13K miles on it, and the in-service date is 9/2009, meaning it's already past the 30 month spark plug change according to maintenance schedule 1. I want to stay in Mazda's good graces for warranty coverage. Should I change my plugs? It seems kind of absurd to do so -- do they really degrade when not used? My ignition system is fine and I'm getting close to 19mpg.

Your input is appreciated.

Thanks,
Brian

 

You could change it, but its usually every 30k miles...

 

I've seen some pictures on here of some pretty fouled up plugs with only 19k miles on them.

Pop them out and take a peak? When I changed mine on my 2009 at 25k miles they made an obvious difference in engine performance. The plugs I removed were very dirty (IMO).

 

It is pretty hard to replace the plugs too early on a rotary. They get dirty REALLY quick. Time doesn't mean as much to the plugs though, so if you want to hold off another 10,000 miles, you are probably fine. Keep in mind that the Mazda schedule doesn't list coil replacement, and replacing the coils is a critical part of proper maintenance as they fail on average about every 30,000.

 

Thanks for the feedback! I think I'll have a look at them in the near future and go from there.

 

sounds like a good idea. if the car is running good, and its not flooded or anything, you should be able to get close enough to 30k on the plugs.

they will come out looking ugly, but looking ugly is fine, you're worried about how worn they are.