I've always used NGK BR9EQ-14 spark plugs and it looks like I can still get them through RockAuto. All the auto parts stores only show the NGK BUR9EQ for our cars.

Has anyone used the NGK BUR9EQ? What is the difference?

 

I think the U means surface discharge. Probably work fine, these are used in FC and FD normally.
I have the rx8 plugs in my leading and they work great.

 

When I looked it up it seems to be one of the optional RX-8 plugs.

It seems like the RX-8 guys use either the BUR7EQ or BUR9EQ.

 

You are advised to have a direct fire ignition system is order to use surface discharge plugs.

 

Good to know, thanks.

I will just stick with the stock plugs since I have no plans to go direct fire.

I've always used the BR9EQ-14 but it looks like RB and Mazdatrix say to use the BR8EQ-14. Should I try and find the BR8EQ-14 or stick with the easier to get BR9EQ-14?

 

Stick with 9. You are the owner of your car, not them.

 

+1 on that, I forgot all about it, thanks Jeff.

 

Thanks All

 

with NGK, the numbers mean stuff, i'm not 100% up to speed but....

the BU/BP/RC, etc refer to the plug design, there are a TON, but basically every car on the planet that isn't rotary takes a BP.

the R is for resistor, no R = no resistor

the number is the heat range, 9 is colder than 7. you want the stock heat range, unless you're modded or step on the gas a lot, then you want a colder one.

not sure about the EQ

if there is then a P or I its platinum, or iridium, if its blank its copper.

so a BUR7EQ is a copper, 7 heat range resistor surface discharge plug, it happens to fit the FC, the FD is a BUR7EQP.

the Rx8 uses an RC7 something something, and its much much better. it is a fine wire iridium plug, based on the race plug design. it is less shrouded than the other plugs, and it misfires less, AND it takes less ignition power to fire

 

And it's working great in my stock 12A with a direct fire ignition.

 

Has anyone tried to use the RX-8 plugs without direct fire? I know it would be an expensive experiment.

 

I'm not sure the stock ignition setup would have enough power to get a good spark out
of them. Only one way to tell though.

 

Now you guys have me interested in RX-8 plugs. I might try a set on my leading.

 

Do it, you wont be disappointed and they wear longer, hopefully. Little pricey but
if they last then its worth it.

 

I usually replace my plugs every 6 months max. If the RX-8 plugs would give me 1+ years, I think it would be worth it.

 

Yeah, with DLIDFIS, that is twice the number of sparks for the same mileage the plugs were originally developed for, thus my leading plugs wear kinda fast. I use BR8EQ-14

 

it takes less power to fire the Rx8 plugs, so it actually is more beneficial to the stock setup. i've done it, works great, BTW

lol, i've had my Rx8 for more than 3 years and 20K miles, and i haven't changed the plugs yet, they last a long time

 

I'm going to have to try them.

 

I'm going to try the 8 heat range RX-8 plugs with boost. They are hard to find in this country though. And expensive!

j9fd3s said, "n3z1-18-110a is the Mazda number, NGK calls it a RE8C-L"