Best Spark Plugs for Fuel Economy?

[Mitz]

...
I would be willing to give these a shot, BUT I can not find any place selling the LFR5AHX plug which is the one that fits our Mirage 3A92 engine. So, nobody is selling them quite yet, and we have no idea what the price is.

I am looking forward to buying them when they will be widely available.. my search yielded only two sites:

CANADA
http://www.clubplug.ca/en/products/d...obber/desc/180

TAIWAN >> LFR5ARX-11P (equivalent but costs more)
https://japansparkplugs.com/boutique...r5arx-11p.html