I see the consensus is bpr6es because there copper. I then noticed that they are nickel now. The stores carry the nickels ones only. I would have to order the coppers. Does this matter. I have searched looking for this answer.
Your local parts store will have the BPR6ES. The reason they are trying to sell those to you is because that's what comes up in there system. Tell them to just check for a part number "BPR6ES" they don't need to know what type of vehicle your driving. I actually just purchased my BPR7ES couple days ago.
On the BPR6ES, The core will still be copper, The copper core conducts electricity and promotes heat dissipation, and the nickel-alloy is used to pro-long spark plug life.
It's not, "copper or nickel core". both elements have to be used.
The reason why is because, due to copper's soft nature and low melting point, using it as an outer electrode material would result in a plug that lasted only minutes.