• Captain Aggravated@sh.itjust.works
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    3 hours ago

    The maximum weight for a tractor-trailer rig in the United States is 80,000 pounds, 40 short tons or 36.36 metric tons.

    A tractor-trailer rig is surprisingly streamlined. The cab is shaped and sized for the front of the trailer to ride closely in its wake, often with fairings that reach as close to the trailer as practicable. Sure it’s a brick, but it’s ONE brick:

    A pickup truck towing a trailer isn’t anywhere near that slick, even with a gooseneck trailer, the trailer is often taller and wider than the cab. It’s a brick, attached to another, larger brick being pulled through the turbulent disturbed air from the first brick:

    In terms of torque, EVs have a significant advantage. Electric motors produce a lot more torque at low to zero RPM than internal combustion engines do. Limited slip differentials or all-wheel drive are solved problems.

    The additional energy required to accelerate the additional weight up to speed isn’t that much of a problem as an EV will get that back with regenerative braking. Well, some of it. Most trailers have brakes of their own that do help with braking distance but are there mostly to keep the hitch under tension to prevent jackknifing. An ICEV figures on losing all of that energy to friction braking, a BEV plans on recovering some of it. An electric pickup carrying 1000 pounds in the bed will be more efficient than one pulling a 1000 pound trailer, in most cases.

    • fizzle@quokk.au
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      1 hour ago

      The maximum weight for a tractor-trailer rig in the United States is 80,000 pounds, 40 short tons or 36.36 metric tons.

      I’m not sure what you’re getting at with this. Here in Australia road trains haul 90 metric tons of grain and fertilizer all the time, that doesn’t include the weight of the trailers.

      Regardless, I’m not quite sure what you’re trying to illustrate - your example of a “streamlined vehicle” undoubtedly consumes a lot more diesel than your example of a vehicle which is not streamlined. Isn’t that antithetical?

      In terms of torque, EVs have a significant advantage.

      Yes, but a “truck” with a 4 ton towing capacity obviously needs motors with more torque than those on a tesla.

      The additional energy required to accelerate the additional weight up to speed isn’t that much of a problem as an EV will get that back with regenerative braking. Well, some of it.

      As little as 5 to 10% on the highway, not particularly significant. Installing regenerative brakes on a trailer is a lot of additional cost and complexity.