Originally Posted By: JHZR2
Delco, IIRC, had the most batteries consistently across the top two or three, in all of the various sizes.
Delphi's battery business has been assimilated by Johnson Controls, which makes Interstate, Motorcaft, Autozone Duralast, Advance Auto Autocraft, Costco Kirkland Signature, among others.
As a result, most AC Delco batteries are now made by Johnson Controls and physically identical to Johnson Controls batteries sold under other brand names.
I never thought I'd see an AC Delco battery with removeable vent caps.
Incidentally, all these Johnson Controls batteries are generally available in 3 performance levels, good, better, and best, with the best warranties and CCA ratings on the most expensive batteries. (The exception to this is some of the less popular group sizes like the Euro group 40R/47/48/49 batteries, which are available in only one CCA rating).
Interestingly, Costco sells the "best" Johnson Controls batteries with a 3-year free replacement warranty for about the same price as most other places sell the "good" battery with an 18-month free replacement warranty, around $50-$60 depending on group size. They don't even seel the "good" or "better" batteries.