-90gtu-

i was on rx7world.com going to purchase spark plugs for my 90' gtu N/A. When i found them they were listed as

leading city (hot)
leading highway (cold)
trailing city (hot)
trailing highway (cold)

im not exactly sure why they are like that, i haven't seen them labeled like that before. and im also not sure if it matters where i put what leading, or trailing spark plug. ne idea's????


thanks

micah

Just get the normal NGK 9's and 7's Whats wrong with those?

Get two of each: BUR7EQ (leading) and BUR9EQ (trailing).

fc3sna

the cold are performance plugs, they have a hotter spark, low rpm driving burn them out quicker. the hots are the normal spark plugs probly. i think thats how it works

yeti

iTrader: (1)

Yeah I'm running 7/9s now I think when I change them I'll go with 6/8s... Which are the 'city' plugs. Probably not that big of a difference And will probably help with gas mileage (atleast in the winter where I only drive to work and back so the car doesn't get any miles. so it never really gets to warm up)

micah

I really doubt running different plugs will help at all.

ericgrau

iTrader: (1)

look it up at www.howstuffworks.com

If your plug runs too cold, deposits build up without burning away (fouling)
If your plug runs too hot, the plug body could ignite your fuel before the spark does, making your engine knock.

"Performance" plugs are cold so that they won't get as hot when used in hotter engines (i.e., those that are pushed harder or that make more power). I doubt they improve performance at all. Plus they'll foul faster in a regular engine.

-90gtu-

so wud it be alright to run one of each of those, or wud it be a bad idea to mix them???

arghx

iTrader: (3)

holy crap dude, it's an N/A. Just use 7's for leading and 9's for trailing.

ericgrau

iTrader: (1)

Those are the plugs you are supposed to use. Just use those. If you walk into any auto store and tell them you need plugs for a 19XX Mazda RX-7 I believe they'll give you those even if you don't remember the name yourself.

I suppose if you ran 2 plugs that were too cold and 2 that were too hot you'd get knocking and the 2 cold plugs would foul.

micah

Are you serious? wud?

RETed

No, they don't.


-Ted

micah

You crack me up man. Such a smart ***.....