Interstate is made by Johnson Controls Inc (JCI). It's an excellent battery. JCI also makes the Autozone Duralast/Gold batteries. Autozones are all over, and for warranty needs if you're on the raod just can't beat it.
AC Delco is getting harder to find, which means it may be harder to replace on a road trip than Durlasts. Otherwise I'd prefer the AC Delco maintenance free battery. I think it's an excellent battery and the old ones I'd seen just about don't vent any acid vapor out the caps. Can't beat the 50-month free replacement period for the 7-year top line. many others are up to 3-year free replacement. Some of the cheaper ones look like they have the JCI caps. So I'm not sure how much of Delco is still the original Delco.
I wouldn't touch Exide batteries. I think NAPA sells these. The JCIs have caps with cut corners. Others have said the Exide ones have round corners.
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