What Harvey says was admitted to me by the local interstate battery store.
Napa told me their batteries were interstates, and were about $10 less each. But, I didnt believe him. The main reason I didnt believe him was because the warranty at the interstate store was quite a bit longer. But that was my mistake. I went ahead and bought the batteries at the interstate store because I was running out of time that day, and just wanted to get it done. (So my hurry cost me $20)
Now the napas were black like the OEMs. And the interstates from interstate are white. I dont know if they have different qualities that they send to different retail outlets or what. But the bottom line is that the interstate store is just a retail outlet, not the mfg.