[iamnotahippee]

I am not sure on the mudflap either. I am thinking some belly panning may be useful. Idle time is just a way of life with a diesel, or atleast a turbo diesel. If you are run in hard, the turbo needs to cool before you kill the engine to prevent excessive heat soak. Now excessive idling is detrimental also, so it is a fine line. The hard part about adding a bunch of big batteries is they take up alot of room. They can't go on the bed, there is no room under the hood. The only real option is installing another toolbox under the body and putting them there. Now that option is in the works, primarily to address a voltage drop issue I am having when I hook up my trailer and use the winch on it. I haven't done the figuring yet to see how much battery I would need, but it would not be unusual to need to run my 12.5k winch for 15-20 minutes on one sitting. It pulls enough juice that if I have it running under a good load for more than 30-45 seconds I have to let off and let the truck build charge back up.
another consideration is cost/benefit analysis. Driving 55 would help fuel economy, most definitely. But if you have 300+ miles to run in a day, the fuel economy hit of 65 mph sure starts to look miniscule, especially when you are oversized and can't run after dark. That 30 minutes could be the difference between making it home without a ticket or not. I do try to keep the speed down when time is not as much of an issue, but those times are somewhat rare.
Extra battery storage to reduce idle time...so probably looking at easily $150 each for batteries, twice if I add 2. Then $300 or more for a quality underbelly box. Conservatively $50 for the odds and ends to wire it all up. When I consider for $1300 or so I can get the injector replaced, the batteries get me half way there, and may be more benefit in the end.
I will say, on my empty mileage from above, 120 miles or so of that included going to help my wife after she had an accident on the way to work with our kids with her, and then me headed to work running very late. So I was definitely not driving for economy sake. I am hoping this week I can get some more numbers to pull from and see where we are economy wise.