Originally Posted By: Nick1994
Spark plugs aren't a one size fits all.
IMO what's best is what it came with. Jeeps like Champion, Toyotas like Denso & NGK, GM's like AC Delco etc.
This has been my experience also.
GM cars really prefer Delco. Asian cars really prefer NGK or Denso. Bosch is the plug of choice for a VW.
I have found that Bosch plugs are most likely to work pretty good in other applications. But I have always found that the OEM brand performs best. I may go up or down one or two steps in heat range, but I always stay with the brand.
The worst plugs I have ever used are Champion. I've only used them once, and that was probably over 30 years ago, but the engine ran horrible. Perhaps they are better now, but you couldn't pay me to put a set of Champion plugs in a car. I won't even use them in my mower, snow blower, or other yard care equipment.