Upgrading spark plugs
 

I'm about to do a full tune up and I figure I need to change my plugs (also to maybe combat the horrible mileage I've been getting)- does anyone have any ideas about what to use for an upgrade? Brands, type, anything.

Thanks!

Stock is best unless you have an upgraded turbo car or race car. People also sometimes like running the BR9EIX series iridium plugs for durability, however they are quite annoying to install. These cost the same as stock plugs.

NGK! How hard do you drive? Do you race (i.e. above 7k rpm constantly)? The recommended plugs are as follows:

"Around town"
Leading: BUR6EQ
Trailing: BUR8EQ

Stock plugs, turbo and n/a (may be too cold for around town)
Leading: BUR7EQ
Trailing: BUR9EQ

There's basically no reason to not use one of those combinations, unless you have a monster race engine. Those come from here:
http://howto.globalvicinity.com/gv_w...i=62&co=1&vi=1

(if anyone has improvements, modify that page)

run stock plugs

If your mileage is shitty, replace your o2 sensor, airfilter, plug wires (OE NGK work great) and get a MSD 6a or Crane Hi-6 ignition amp for the leading (twin) coil

So just to clerify for someone that is a complete idiot and takes it to 7+K every chance he can (me) , you would recommend
Leading: BUR6EQ
Trailing: BUR8EQ
? I have an 88 n/a 90 compression :0P

I've been going with MazdaTrix's recommended plugs (they supplied the list I gave), and even though I drive spiritedly too, I've found the BUR7EQ/BUR9EQ option fouls faster than the BUR6EQ/BUR8EQ option I'm running now.

wow, so the next time i buy spark plugs would be BUR6EQ and BUR8EQ...

My friend told me that it was actually best just to stick with the stock plugs unless you've really changed a lot of the car. He figures the engineers would have picked the best plug for the engine.

yeah guys stock NGK plugs r best

Well, it's a lightly modified TII (intake, mufflers), but it's only going to get more modded as time goes on.

When my T2 was slightly modded I was running 4x BUR9EQ. Then I started running 4x BR9EIX. Worked great and the plugs last forever. May as well go to colder plugs if you are gonna be pushing the stock EFI.

Just go the stock 7/9 route for now. You can inspect the plugs later and see how fouled they are. If they foul early, it may be because they’re too cold for your driving style. That’s why I switched to the 6/8 combo, which has worked well for me.

edit: nik's suggestion is good too, might be good to listen to a turbo guy!

I run 7/9 in my vert, with it ported.

I just changed the plugs recently with ngk plats, so I'll know soon enough (round town 99%, with a little long distance highway driving 1%) on the fouling issue.

I just wanted to say two things:

One, definitely stick with ngk. good plugs.

Two, the point some people make about the engineers, and the best parts. Now, this sounds great in theory, but many factors go into manufacturing a car, and putting it all together. The most important factor being cost.

If the engineers had their way, only the best components would be used, and nothing would be "sub-standard." However, as many can attest (I being from the comp industry), doing things the right way is not the same as doing things the economic way.

Some parts cost more, some manufacturing processes cost more. In our economic system, that's how things work. To think that everything would be perfectly made, designed, and thought out is idealistic at best.

And, if you people need an example, here's one: the electronic systems in our cars. If the electronics were done as high quality as everyone would assume, why are there problem areas such as the logicon, headlight/wiper switches, etc.?

Just goes to show you, assumption is the mother of all f*ck ups.