What type of spark plugs do you use?
 

I called AutoZone and they have several spark plugs available for my 85 (12A). I'm used to using the NGK BR9EQs, but I'm willing to experiment. Have you used any of these plugs?

NGK all the way. I use BR9EQ-14's on the trailing and BR8EQ-14's on the leading.

NGK! nippondenso's suck. The insulator cracks on them in my experience.

What's the advantage to doing that? Just curious...:)

same thing happened to me that why i only use NGK's

I cheaped out and bought some autolights ( I was eating rice 3 meals a day as it was, so give me a brake :) ) Long story short a few day's later I got NGK's. I think they're the best plug for 7's, all else I'll use bosch.

The thing is though, there's gotta be a comparable plug to the NGK that is cheaper. The Bosch Super is only 99 cents, but maybe it's not so great?

By the way, how long do those NGK BR9EQs last for normal driving?

NGK BR9EQ

I have used them for about 2 yrs...

Anything OTHER than NGK is just plain dumb..

Autolight is a cheap cop out,
Bosch 4 is the same as the NGK but I stil prefer the NGK

4 Prongs plugs

I run the same plugs in a FD, but I run 9's all the way around and in platinum :D

I have used NGK BR9EQ-14s in all my SE's and NGK B9EV's in my street-ported 13B.

Don't look at the Autozone web site actually go to or call an Autozone. There is only one correct listing in the computer, the Denso 3104. The iridium is also listed but not available yet. The Denso is what I use and several other 7 owners use in this area and I've never had a problem with them. The other plugs that are listed on the web are incorrect. Bosch does not list a plug for the rotary, and the 4 ground design is different from NGK and Denso. The others are just single ground and are not designed for a rotary either. If the people at Autozone have any problems tell them to call me (Aaron)at store #1647, and I'll get them straigtened out.

In my first post, I stated that I called AutoZone, and the guy I spoke with initially told me he had the Autolite plugs. Not knowing what Autolites are like, I asked him to tell me the other plugs that he had in stock, so he did. Just wondering if there was a slightly inexpensive plug that was comparable to the popular NGK.

Autozone does not sell Autolite plugs and the other plugs you listed don't show up on my computer screen when I look them up in my Autozone store that I am the Manager of. I have seen them on the website listed that way, that is why I wrote that, As far as price The Denso's are $3.99 ea and the best I could find NGK's for was $4.99. There is your answer. BTW SA's came stock with Denso plugs. They can't be all that bad.

Yeah, who knows what the guy I talked to was looking at. Thanks for the correct information though. You saved me a trip :)

NGK B9EV

what does this plug look like???

Like a conventional single prong plug.

I run the B9's per davids advice and they work great

The trailing plugs, from what I understand, endure a lot more heat than the leading, that's why I run the colder "9" plug. You'll also notice that Mazda started recommending colder trailing plugs for all rotaries after 1986. <speculation> Perhaps this is because Mazda learned something about spark plug behavior and decided to make it a mfr recommendation. </speculation>

Cool. But aren't the hotter plugs prone to foul faster than the cooler plugs?

Other way around. Hotter plugs retain more heat in the plug which allows it to burn off deposits and remain clean.

B9EGV, leading and trailing in a S5 13BT.

Hey can the B8EG or B9EG be used (without the V) without any problems?

I'm using B8EVs now but can get the B8EGs or B9EGs cheap too.

Well, whatever you do check the electrode depth. I've been told (tho it hasn't happened to me) that an unknowing mechanic put American plugs in a friends car that protruded into the swept area and chipped the end seals. Oh woe! Also, I think you want to use the 4 electrode jobs for reliability, and it's often hard to beat the mfrs original equipment. My original NGKs lasted many years. Finally I changed them just on General Principles.

B