That's not how these calculations work at all. Weight (if it doesn't change the size or shape) really only has an effect on rolling resistance, which is a small portion of overall losses.
The extra weight should make a marginal difference in efficiency. Just expect more tire wear.
That seems to be a rather simplified view, as if stemming from the world of frictionless pulleys and rope that does not stretch.
These are self-propelled electric vehicles that have regenerative braking. Regen is miles ahead of just dumping momentum as heat [as conventional brakes must] but it can never be 100% efficient -- and it may not even be able to begin to try to capture 100% of that momentum in the first place, depending on the particular braking circumstance.
These characteristics weigh heavily on how such vehicles perform in the real world, especially when the terrain is not flat. (And in this test, the terrain was not flat.)
I wrote an electric vehicle power / efficiency / range estimation program back in college when I was very into building electric bikes. (More advanced version of the ebikes.ca calculator for an example). There were a whole lot of parameters that went into actually estimating the performance, but the general rule of thumb was rolling resistance is pretty much worth ignoring (for efficiency) until you have spent time optimizing aero and drivetrain losses.
It was pretty damn close to real world measurements.
I'm going to use rules of thumb rather than exactly calculating things for a colloquial conversation online.
Doesn’t weight have a massive effect on power needed for acceleration ? To go from A to B You need to get up to speed but also acceleration for regulating your speed after taking a turn, crossing a traffic light, passing someone over…
If we ignore air resistance, then weight and time are the only variables needed to determine the power needed for a given acceleration. Force is related to mass through "F=ma", and power is effectively force over time.
Though, neglecting air resistance is a huge deal. A cyclist traveling over 20mph is spending something like 90% of their energy at that point overcoming air resistance. For objects travelling faster, it's a square low of how much more power is needed. Air resistance is a very huge effect. With that said, if travel is dominated by accelerating and decelerating (eg: urban or mountainous environments), then yeah - weight is a huge big deal.
Newton's laws of motion would like to have a talk with you about those statements. A heavier vehicle absolutely needs more energy than a lighter one when all other factors stay the same.
The majority of energy expenditure is not acceleration and deceleration (especially on an EV with regen braking). At moderate and high speeds wind resistance dominates. At slower speeds rolling resistance is a largish factor.
> Does the energy you put into the system just go puff?
Yes, actually. The most common example of this is drivetrain power loss, which EVs are not immune to. Tesla engineers have stated that they are ~15% which is about the same as with ICE vehicles.
While a heavier vehicle at times needs more energy - trains are a counter example to consider. Magnitudes heavier, but do not need magnitudes more fuel.
Which comes to Newton's laws of motion, the two concepts of inertia and Newton's second law: "F=ma", come into play. If the course is a straight 100 mile segment with no elevation gain - then the dominant fuel expenditure will be counter-acting aerodynamic drag. When trains haul many cars, the train cars are drafting behind one another, meaning those cars do not need any force to overcome drag, just the lead car needs to do that.
So, places where trains do badly, will be places where weight matters. Urban environments when stopping/starting a lot - trains will keep it slow. Very hilly/mountainous courses - trains "nope" that and require shallow grades. Which goes to show, if you're spending most of your time fighting gravity - then weight is really important, if most of the time is fighting aerodynamic drag, then weight becomes less important as aerodynamic drag decreases. For example, it does not matter as much how heavy a bullet train is, the drag coefficient is a better indicator of overall fuel cost rather than carry weight.
I'd love to see how you derive that from Newton's Laws of Motion, which are all about acceleration. All other things being equal, it takes no more or less energy to keep a heavy object in motion than a light one. After all, a pendulum's period is proportional to its length, and not its weight.
The cyber truck can tow more than twice the payload. My Jeep can probably tow a couple jet skis further than my friend’s Ford F35O can tow his 26’ gooseneck RV. Who cares?
Agreed. An Audi station wagon can (and commonly is seen) tow a horse trailer comfortably.
It's mentality. In the US, I've seen attitudes of "well, I move my horse twice a year from a summer to a winter pasture" which apparently equates to "... so of course I need an F-350 Superduty DRW ("dually")."
Not when range is a concern -- efficiency directly speaks to range, and it's towing range which is the primary weakness of EV trucks. If you just wanted to haul heavy loads in the bed, I wouldn't necessarily think that an F-150 Lightning or Cyber Truck are all that inferior. (just too expensive)
Yeah, they do. When towing a couple horses across state lines I don’t want to subject those poor animals to stopping every 90-100 miles for an hour to charge. I don’t even want to subject myself to that.
Fuel efficiency is absolutely a concern with regards to operating costs. The people that really need to haul things absolutely care about how expensive it is to run a vehicle.
Tell us you live in the suburbs without telling us you live in the suburbs (come visit some country folk, or work with construction crews on a regular basis to change that opinion)
Lmao, tell me you truck cosplay without telling me.
The vast, vast majority of construction sites don't need a dualie. Hell, half of them don't need a truck. I've seen and met numerous plumbers, electricians, and carpenters who roll up in a van. My uncle was a GC for 40 years. My other uncle was a union pipe/sprinkler fitter. My cousin is an electrician. My other cousin owns a roofing company, and my pops is an architect who regularly makes site visits. None of them owned a work truck. The only one who does own a truck is the roofer who got a Raptor for fun.
The majority of truck owners do not haul large cargo. The majority of construction workers do not bring tools requiring a bed each day. Lawn crews use trailers for their actually large equipment. With fewer and fewer exceptions each year, trucks are increasingly bloated emotional support vehicles for insecure and obnoxious turds.
While you were right in calling that an exaggeration, the only people who I've ever seen use a dualie for real work were all towing horses.
Yes a van is all you need for that. To say you don’t need dualies at all is a joke. What happens is that the dualies are used for heavy equipment but then they double as a vehicle for employees and are given to them as a perk. As such dualies are seen driving around without “being used” or sitting in driveways of McMansions. But thats simply because it’s used as a perk for employees. Very few people are dropping $80k for a f-250 or bigger for cosplay.
Sometimes they need the bed to haul things that a f150 is fine for but they need the cab space to take 6 people plus their gear between jobs
For highway driving, in most places, aerodynamic drag is far more important than weight. I get nearly the same gas mileage towing a 1.5k kb ATV trailer as my dad gets pulling a 7.5k trailer.
The frontal area of both trailers is roughly the same. They both need about 150 horse power to tow at 70 mph.
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[ 0.26 ms ] story [ 103 ms ] threadThe extra weight should make a marginal difference in efficiency. Just expect more tire wear.
These are self-propelled electric vehicles that have regenerative braking. Regen is miles ahead of just dumping momentum as heat [as conventional brakes must] but it can never be 100% efficient -- and it may not even be able to begin to try to capture 100% of that momentum in the first place, depending on the particular braking circumstance.
These characteristics weigh heavily on how such vehicles perform in the real world, especially when the terrain is not flat. (And in this test, the terrain was not flat.)
I wrote an electric vehicle power / efficiency / range estimation program back in college when I was very into building electric bikes. (More advanced version of the ebikes.ca calculator for an example). There were a whole lot of parameters that went into actually estimating the performance, but the general rule of thumb was rolling resistance is pretty much worth ignoring (for efficiency) until you have spent time optimizing aero and drivetrain losses.
It was pretty damn close to real world measurements.
I'm going to use rules of thumb rather than exactly calculating things for a colloquial conversation online.
Though, neglecting air resistance is a huge deal. A cyclist traveling over 20mph is spending something like 90% of their energy at that point overcoming air resistance. For objects travelling faster, it's a square low of how much more power is needed. Air resistance is a very huge effect. With that said, if travel is dominated by accelerating and decelerating (eg: urban or mountainous environments), then yeah - weight is a huge big deal.
I hate when people make smart-ass claims with surface level knowledge at best.
Yes, actually. The most common example of this is drivetrain power loss, which EVs are not immune to. Tesla engineers have stated that they are ~15% which is about the same as with ICE vehicles.
Which comes to Newton's laws of motion, the two concepts of inertia and Newton's second law: "F=ma", come into play. If the course is a straight 100 mile segment with no elevation gain - then the dominant fuel expenditure will be counter-acting aerodynamic drag. When trains haul many cars, the train cars are drafting behind one another, meaning those cars do not need any force to overcome drag, just the lead car needs to do that.
So, places where trains do badly, will be places where weight matters. Urban environments when stopping/starting a lot - trains will keep it slow. Very hilly/mountainous courses - trains "nope" that and require shallow grades. Which goes to show, if you're spending most of your time fighting gravity - then weight is really important, if most of the time is fighting aerodynamic drag, then weight becomes less important as aerodynamic drag decreases. For example, it does not matter as much how heavy a bullet train is, the drag coefficient is a better indicator of overall fuel cost rather than carry weight.
I can't think of a single negative thing
EDIT:
Cybertruck (all three versions)
Maximum Towing Capacity. 11,000 lb
Model X has two capacities:
275/45R20 tires + Class III hitch = 5000 lb
285/35R22 tires + Class II hitch = 3500 lb
If all you are ever going to tow is a couple of jet skis, then your jeep would be the better vehicle (if evaluating solely on towing distance).
If you own a trailer like this one and are deciding if you need the Cybertruck to tow it, you have the data.
Knowing capabilities and data helps make better choices.
It's mentality. In the US, I've seen attitudes of "well, I move my horse twice a year from a summer to a winter pasture" which apparently equates to "... so of course I need an F-350 Superduty DRW ("dually")."
[0] https://arstechnica.com/cars/2023/10/elon-musk-talks-tesla-w...
The vast, vast majority of construction sites don't need a dualie. Hell, half of them don't need a truck. I've seen and met numerous plumbers, electricians, and carpenters who roll up in a van. My uncle was a GC for 40 years. My other uncle was a union pipe/sprinkler fitter. My cousin is an electrician. My other cousin owns a roofing company, and my pops is an architect who regularly makes site visits. None of them owned a work truck. The only one who does own a truck is the roofer who got a Raptor for fun.
The majority of truck owners do not haul large cargo. The majority of construction workers do not bring tools requiring a bed each day. Lawn crews use trailers for their actually large equipment. With fewer and fewer exceptions each year, trucks are increasingly bloated emotional support vehicles for insecure and obnoxious turds.
While you were right in calling that an exaggeration, the only people who I've ever seen use a dualie for real work were all towing horses.
Need a skid steer, trencher, scissor, lift or other heavy equipment and you quickly enter dualie territory.
That being said, an F-250, F-350, F-450 are all essentially the same truck. Same engine. Mostly just stiffer suspensions on the heavier duty trucks.
Sometimes they need the bed to haul things that a f150 is fine for but they need the cab space to take 6 people plus their gear between jobs
Most people who do serious hauling pull the bed off.
A Prius might have massively more towing range than an F-350, assuming you're towing a tiny trailer.
The frontal area of both trailers is roughly the same. They both need about 150 horse power to tow at 70 mph.