[Diesel_Dave]

We're getting off topic here, but the issue with hybrids in a highway over-the-road tractor is that there's not much of any benefit. There's hardly any starting and stoping for regenerative braking to help and those powertratins are already set up to keep the engine very near it's "sweet spot" when cruising. Another issue is that the additional weight of the batteries, electric motors, etc. takes away from the payload capacity.

Also, with regard to your comment about driving accesories/idling overnight, a lot of truckers are adding small gensets for that very purpose. I know Walmart has done this to a lot of thier trucks.

That particular market (heavy-duty semi trucks), is THE most sensive market to fuel economy--of any vehicle class. Those guys will sratch and claw for even the samllest benefits. Why? I figured it out once that a 1% improvement in FE for one truck worked out to be >$5,000 per year per truck. Improve the average passenger vehicle by 1% and nobody even cares or notices.