In addition to nearly smoke-free operation, OptiMax burns 45 percent less fuel than conventional outboards. Fuel economy aside, the 115 OptiMax features a belt-driven 60-amp alternator to run ancillary electronic equipment. And that's not just at cruising or top speeds. The alternator delivers 44 of those 60 amps at 1,000 rpm. Using an erasable memory system, the ECM draws no power when the key is off, which means batteries that sit last much longer.