Gentlemen;
It doesn't make ANY difference who makes the plugs. The important thing is: Is it the right heat range and set properly??
This is true for any engine, anywhere in the world, from sea level to 5,000', in the 'artic' or desert.
Now; To determin this, install & set what the factory had and operate your vehicle as you choose. After 2,000 miles 'or so' inspect them.
One of three things will appear. 1) to hot, 2) just right, 3)to cold. Then you make adjustment(s).
As a "general rule" AC works best in GM cars, Autolite in Ford, Chysler & American Motors and Champion for industrial engines.
If you have a Jap car, call Tokyo or Uncle Ben.
Good luck.
