saw these in quadratec, anybody know how well they work? marketed to reduce fuel useage by 3-13% and gain 6-12% power...7$ a piece, worth it, or not?

 

No.

Copper plugs, as everyone else is about to tell you, are what you need for a 4.0. Assuming that is what you have. Champions Pre 97, NGK 97+.

 

yes I have a 98 4.0

the e3 has a copper core, and nickel tip

champion copper: copper nickel alloy core and tip

ngk has nickel tip and core...

what I want to know is if this plug truly would help reduce fuel and add more power

 

Not according to any review I have seen. I have not used them personally, though.

 

Put them in my g6 and gained a couple mpgs. But thats a different engine obviously.

 

Snake oil. At the shop, I remove several sets a month to fix Backyard Billy's home tune up.

Forget E3, Splitfires and all that BS.

 

All BS. when i first got my jeep I replaced the old champions with E3 Platinums. Felt no difference whatsoever. About 2 years later i replaced those with the champions i have now and still felt no difference.