I was buying spark plugs and the dude at checker said he owned a rx7 and instead of putting two trailing and two leading he did all leading, which lead him to a little more horsepower and some better fuel consumption...whould there be any negative results to this?? Or is it a good idea??

 

WRONG and WRONG.

If anything, you can run all trailings - all 9's.
This gives you a little better spark plug LIFE, but it should not change performance.
(Unless the performance and gas mileage is due to the spark plugs lasting longer?)

Lesson?
Don't ******* listen to the idiots at Checkers.


-Ted

 

second that notion

 

Yeah, i have known not to listen to those speds, but it made me wonder... hell if im just going to do something based off what they say... Thanks guys.

 

all leadings will result in pre-ignition or detonation of the trailing, and generally cause knocking (which robs HP- not making more).

The clerk probably told you all leadings because either he didn't have the trailings, or he didn't want to sell you 2 of each and break up a box for his inventory.

 

...or he lugs the crap out of his motor and keeps fouling his trailing plugs.

 

a mix 0f 7's and 9's are only good if you are experiencing poor starting. put four
9's in if you have any sort of mild mods.

 

9's all around if you are seeing problems with detonation. Other than that, stay with the 7's in leading otherwise you may experience fouling problems, or incomplete burn.