Published on November 25th, 2015 | by Kyle Field55
When 12 MPG Is An Achievement
November 25th, 2015 by Kyle Field
The good folks over at Energy.gov shared some SuperTruck goodness that’s just too good to pass up. Not sure what a SuperTruck is? Well, that’s a great place to start. The Energy Department kicked off an initiative called SuperTruck with the specific goal of increasing freight efficiency by 50% compared to a baseline vehicle. Now, that wording is tricky, so let’s break it down a bit further.
Freight efficiency is effectively the amount of energy required to move a given amount of freight. Increasing freight efficiency is accomplished by:
- Increasing freight density — or the amount of freight that can be packed into a standard unit of space
- Increasing truck space utilization — or filling trucks up to a higher fill % instead of shipping partially full trucks.
- Reducing the drag coefficient and overall wind resistance of the vehicles.
- Increasing the miles per gallon efficiency of the drivetrains that move the freight.
- Optimizing air pressure in tires for the load to minimize non-value-add loss due to friction.
You might be asking why the US Department of Energy is working on heavy truck efficiency, and that’s a great question. Digging into the numbers reveals that heavy-duty trucks consume about 20% of the nation’s fuel. On top of that, the general design of these vehicles is similar, meaning improvements in efficiency that relate to aerodynamics, tires, gearboxes, heating and cooling, freight loading strategies, etc, are much easier to scale across a large number of vehicles — which, in turn, can lead to larger reductions in emissions, much more quickly than with passenger vehicles. Most importantly to me, these trucks burn diesel, and even though diesel can enable higher mileage per gallon, it causes cancer which negates any other benefits in my book.
The Energy.gov article spotlighted several specific improvements that the Department of Energy has found to be successful since starting the program:
- Advanced combustion engines burn fuel more efficiently because it’s injected precisely — and at very high pressure — into combustion chambers. This improvement alone can increase efficiency by 20%!
- Aerodynamic features give SuperTrucks streamlined bodies, which cut through wind and reduce drag. These include the flaps under and behind trailers that are designed to reduce turbulence and wind resistance, which ultimately slow the truck down.
- Advanced body panel materials reduce overall vehicle weight.
- Auxiliary power units cut idling time by using rechargeable batteries to provide electric power for cooling and heating the cabin and cargo, rather than running the truck engine itself overnight.
- If all Class 8 trucks used SuperTruck technologies, we could lower oil use by an estimated 300 millions of barrels per year and individual truck operators could save about $20,000 a year on fuel.
- Natural gas (NG) trucks can be a transitional fuel while at the same time reducing emissions. While NG is still a fossil fuel, emissions are typically lower than diesel. The watch-out for NG is fueling and production emissions. Because NG is mostly methane, which is a much more potent greenhouse gas, any fugitive emissions greatly impact the wheel-to-well calculations and may even fully offset any reductions in the actual combustion process.
What’s great is that, while battery electric trucks are not always cost effective, they have found that in specialized applications — like shipping yards, which are hubs for pollution on their own — these fully electric Class 8 trucks can be a great fit. Current models are already getting 60–120 miles per charge with a recharge time of 3–4 hours. That’s pretty much what I’m getting in my Leaf, though I’m sure they’re packing much larger loads of batteries. I guess size does matter….
They also have a video that nicely summarizes and shares a lot of the neat tech they are working on to improve heavy-duty truck freight efficiency… here:
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