1: The cost of the gas engine is offset by the reduction in cost and weight of a smaller hybrid battery. 2: Hybrid buses are already a thing, and they're subje

1: The cost of the gas engine is offset by the reduction in cost and weight of a smaller hybrid battery. 2: Hybrid buses are already a thing, and they're subject to even more usage and wear, and work very reliably. 3: Cheaper maintenance as an absolute number isn't the goal, but a reduction in total cost of ownership. Remember there's a bunch of gas that's not being used or paid for. The lower the starting MPG, the higher the benefits electrification brings.