I would use split fire
a/c delco is the best
whatever the factory recommends.
The stock plugs are best
what kind of car?
A/C Delco and put the # in it that it calls for from the factory.
Motorcraft Platinum Plugs.
Our concrete saw uses that kind of spark plug
The 2014 Chevrolet Spark has a 5-speed manual.
The 2013 Chevrolet Spark has a 5-speed manual.
Its best you use the fitted platinum tip ones (no adjustments needed). You can find these at NAPA.
if you call autozone or checkers they can tell you over the phone which is best and if they have any instock and what is closest to you