How long have you had this in your engine? If you are really getting better MPG I'd like to see a comparison. I did this a few months ago myself when I switched to the long-reach NGK plugs...

 

This is not part of this conversation but it's along the same lines...

I find it SO hard to get accurate mileage checks out of standard use cars. There are SO many variables that will affect mileage there's no way to accurately measure the changes unless they are drastic (5+mpg or more).

somedays in my p5 I get 32mpg and some days I get 24mpg..it sucks.

 

I would agree...but, my driving routine from week to week is basically exactly the same. I drive the same route to work then to school and then home. This is basically my driving habits during the week, this changes very little. Now the weekends are a different story. But for the most part my drivng habits don't vary much from tank of fuel to tank of fuel. I have basically been getting 26 to 27 miles (city) to the gallon each tank of fuel. With this stuff when I fueled up last I calculated between 28 and 29 mpg, which I know isn't a big difference but it is a difference. I expect the results will be better with highway miles.

 

I have only had this stuff in my engine for a couple weeks now, but I am seeing some difference. Did the plugs help at all ?

 

Well, let's put it this way: my assessment wasn't any more scientific than yours!
However, the NGK ZRF5F11's are used in the j-spec engine. Also, they were recommended by several other members including the Lord of Protege owners and writer of the Protege FAQ, theMAN.
My personal assessment was that it smoothed out the power band. Stock Proteges tend to hiccup a bit between 3+4k and the plugs stopped that.
I figure, even if there is no benefit, they are no more expensive that the stock plugs and that's better than spending 40 or 50 bucks on plugs that do nothing.