I put a 6V Optima battery in my Franklin this year. I never had any problems with the 6V system or its performance, but the cost of the conventional 6V lead/acid battery finally climbed high enough to where the Optima was only a few bucks more. That, combined with Optima's claim of double the lifespan of conventional batteries, made me buy one. I've only been running it for one season, but I will say this, the car now cranks faster, charges at a higher amperage, and the lights are brighter. I was only getting 4-5 years out of a lead/acid battery, as is expected. If the Optima lasts even two years longer, it's well worth it. Also, the Optima only weighs 18 lbs. I don't sell Optimas, nor do I have stock in the company. It's just a great product for antique cars.