[marktwain]

Is there any NET change. Most likely and increase in total cost and energy if you really looked at it.

It depends on the cost of this trailer. A 36% reduction in fuel costs, for semi-trailer trucks, is a significant amount of money. For every 8.8 miles of driving, .369 gallon of fuel is saved.

So, for every 1000 miles, 113 gallons of fuel saved, at $5 per gallon, $209 per thousand miles, or about 21 cents per mile savings. At an average of 45,000 miles per year, that is a savings of $4,309 per year.

We cannot know if there are overall savings unless we know the cost and operating cost of the units.

[Tell It Right]

Like you, we don't know the net savings until we know the cost of operating this.

And I agree with your math on fuel savings. With that in mind, don't forget the math on cutting labor costs. For example, if the electric motor(s) of the trailer can keep the truck moving at top cruise speed even going uphill with loads, that means faster average speed and, therefore, less driver time per 1,000 miles. Or put another way, more miles driven per day (within the NTSB's allotment of driving hours per day per driver) means less hotel stays.

But then there's the cost to charge the trailer battery, assuming it operates like a plug-in hybrid.

[Alas Babylon!]

Good analysis.

It doesn’t say what charges the battery; I’m assuming the diesel engine up front. What’s the power consumption in fuel on that?

[MV=PY]

"Is there any NET change. Most likely and increase in total cost and energy if you really looked at it. It depends on the cost of this trailer. A 36% reduction in fuel costs, for semi-trailer trucks, is a significant amount of money. For every 8.8 miles of driving, .369 gallon of fuel is saved. So, for every 1000 miles, 113 gallons of fuel saved, at $5 per gallon, $209 per thousand miles, or about 21 cents per mile savings. At an average of 45,000 miles per year, that is a savings of $4,309 per year. We cannot know if there are overall savings unless we know the cost and operating cost of the units."

For a true cost/benefit analysis, you also need to factor in the embodied energy of the equipment and disposal costs.