I put a Costco Interstate in my Taco.
Works
I haven't used a Costco starting battery. However, I have 6V golf cart batteries in our camp trailer. The Interstate GC batteries Costco sells are not the same as the ones sold at the Interstate stores. Look at the labels. Power storage in deep cycles is measured as Reserve Capacity, RC. This is the number of minutes a fully charged battery at 80 ° F will discharge 25 amps until the battery drops below 10.5 volts. The RC on Costco's version is about 110 min. On the green top Interstates, RC is over 400 min. That's a huge difference. They'll cost 50% more but give you 400% more storage.
