Although they’re supposed to be good for 100K miles, it’s probably time to change my plugs after about half that time. I no longer have a long commute, so it would make sense that normal wear items would need replacing sooner due to the increased stresses of 95% city driving. Thankfully replacing them on the Mazda5 is an easy task, unlike the ol’ Windscar where you could only reach the rear bank of cylinders from below.

So, are there any differences in spark plugs these days? Any favorites out there? I used to be partial to the expensive Bosch Silver plugs, but that was 30 years ago and I’m sure things have changed in the last few decades.