When to replace stock sparkplugs?

[ConfuciuS]

My Si has a little over 38,000 miles and im wondering when i should replace them. How long did your guys plugs last before replacing? And what kind is a good replacement? Thanks

[VTEC_DeSTiNY]

Every 15k-20k miles.

NGK V-Power or Iridium or Platinum are good.

Bosch are good, too.

[CivicSiRacer]

I had to replace mine after 5K miles. Autocrossing hard the first year burnt my plugs to nothing. Put new plugs from Honda in and burnt them out in about the same time. So I went to Bosch Platium 4 plugs and 20K miles later they still work great.

[PupaScoopa]

I had to replace mine after 5K miles. Autocrossing hard the first year burnt my plugs to nothing. Put new plugs from Honda in and burnt them out in about the same time. So I went to Bosch Platium 4 plugs and 20K miles later they still work great.

That's weird, I did a full season of Autocross and 50,000mi of normal/moderately hard driving and they looked descent when I changed them (and the wires).

The recommended is over 100,000 miles I think, which is too much.

[dballer19]

i change mine every 10,000 miles, i like to keep my car running the best i can and im very weird about things like that though

[OSOVTEC]

i heard from lots of people that denso iridium was the absolute best...

[You_Get_Vapors]

I think 30,000 miles is a good time to change the plugs. Even if your car is not heavily modded. Just cause you know you get on it enough. I live in a four season state so its not that hard on my car. But if you live in a state like Cali I would recommend it. My car is coming up on 30,000 miles so I thought about doing the plugs and wires(even though I dont really need wires) and getting the valves adjusted(last done at 15,000). I also should get new pads, have the rotors turned and replace the coolant. I just got new tires so they dont need to be rotated and the tranny was just repaired(new gears cause the third gear spring got stuck and they had a service bulletin on fixing they tranny). I might replace the brake fluid too. It's gonna cost hella duckets but I wanna be ready for summertime fun. Peesh