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Tesla Model X vs Toyota Land Cruiser tug of war
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The Toyota is a diesel.
Heavyest vehicle wins. No surprise here.
A much better test would be to add ballast to the Toyota until the weight is the same as the X, then see which vehicle can truly out perform.
Heavyest vehicle wins. No surprise here.
A much better test would be to add ballast to the Toyota until the weight is the same as the X, then see which vehicle can truly out perform.
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Yup, pretty silly. "In the pork weight contest, Tesla model S wins!"
I think the mass was irrelevant. I'd think the factors were, in order of importance:
1. Top of the lne studded snow tires vs. standard tires
2. More torque vs less torque
3. More HP vs. less HP
My guess is that if you swapped the tires you'd get a different result, even with the Model S having more torque. If the tires don't grip then it doesn't matter how much torque you have.
If the tires could provide perfect traction then the Model S would still win easily win because of the torque. The Toyota is a diesel, so more torque than you'd expect from such a small engine, but still no match for the Model S electric drive. It's just a matter of more force overcoming less force. The mass is a minor factor. The rolling resistance of the tires is relatively low, and the force needed to move the Toyota would just be Mass X Gravitational Constant X Coefficient of Rolling Resistance.
1. Top of the lne studded snow tires vs. standard tires
2. More torque vs less torque
3. More HP vs. less HP
My guess is that if you swapped the tires you'd get a different result, even with the Model S having more torque. If the tires don't grip then it doesn't matter how much torque you have.
If the tires could provide perfect traction then the Model S would still win easily win because of the torque. The Toyota is a diesel, so more torque than you'd expect from such a small engine, but still no match for the Model S electric drive. It's just a matter of more force overcoming less force. The mass is a minor factor. The rolling resistance of the tires is relatively low, and the force needed to move the Toyota would just be Mass X Gravitational Constant X Coefficient of Rolling Resistance.
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No tickety-tackety sewing machines there, lol Of course those cars do not represent what most drive...
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880 lbs weight difference is substantial, particularly as a fraction of the GVW. On dry pavement with equal tires the heavier vehicle will cause the lighter one to break traction sooner assuming both have enough horsepower to overcome the static friction of the other.
On the other hand, many of us, including Volt drivers, have direct injection gassers that have that diesel-like tickety-tackety too.
The video reminds me of when I used to roll down the windows and drop a gear or two in my Mini going through a tunnel. 998 cc. never sounded so good.
Doesn't work that way because mass cuts both ways. You need to apply the same force to move a vehicle forward or backward. The direction of the movement doesn't matter. In your example the heavier vehicle needs to overcome the same rolling resistance to move both vehicles forward as the lighter vehicle needs to move them in the other direction. Separating the force from the vehicles likely makes this easier to think about. Image two wagons tied together. One wagon carries 1000 Kg; one carries 500 Kg. Will you need to apply a different force to move the two wagons in one direction or the other? If you say "no" then you're agreeing the mass of the vehicles doesn't matter.
This doesn't change if the road is dry or wet or whatever.
FWIW I think this video was designed as PR or marketing for studded tires. On ice studded tires get 25% or 30% better traction. On packed snow not a big difference. On dry roads standard tires give more traction.
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Good points except for one thing. All things being equal on tires, the heavier car has more traction. There's more than just pushing force to consider. The vehicle that loses traction first loses the tug of war.
Up here in the north, in the old days of rear wheel drive it was common to load up the trunk with salt bags to increase traction in the snow. My father used to drop a couple of iron anvils in the back of the station wagon.
If neither vehicle lost traction the one with greater applied torque would destroy the other.
Your wagons example is missing one thing. It assumes the force on both is in the same direction. In the case of a tug of war the forces are in opposite directions. So traction becomes the dominant factor in who wins.
Edit - I stole this:
The term tractive effort is often qualified as starting tractive effort, continuous tractive effort and maximum tractive effort. These terms apply to different operating conditions, but are related by common mechanical factors: input torque to the driving wheels, the wheel diameter, coefficient of friction (μ) between the driving wheels and supporting surface, and the weight applied to the driving wheels (m). The product of μ and m is the factor of adhesion, which determines the maximum torque that can be applied before the onset of wheelspin or wheelslip.
Factor of adhesion - that's what I was looking for.
Edit 2:
This assumes that the Tesla wouldn't destroy itself first.
The strength of the drive train components matters too. And for this I might not bet on Tesla.It's basically sled pulling.
Weight is King. This is why you must pull onto the scales before and sometimes after you compete (if there is debate).
Hitch height is crucial too. This is also measured prior to competition.
Tires are important, but somebody who scales at 8,000lb could be wearing pretty much anything and rape a 5800lb SUV.
This was done on summer performance tires, sled weighs 50,000lb, which you drag through the dirt, the weightbox moves forward until it's virtually unmovable (Full Pull BTW for the Win):
https://www.youtube.com/watch?v=IAbgw0w5_gs
Yeah I start out slow because if I make full boost before I get the sled moving, I bury the tires.
Weight is King. This is why you must pull onto the scales before and sometimes after you compete (if there is debate).
Hitch height is crucial too. This is also measured prior to competition.
Tires are important, but somebody who scales at 8,000lb could be wearing pretty much anything and rape a 5800lb SUV.
This was done on summer performance tires, sled weighs 50,000lb, which you drag through the dirt, the weightbox moves forward until it's virtually unmovable (Full Pull BTW for the Win):
https://www.youtube.com/watch?v=IAbgw0w5_gs
Yeah I start out slow because if I make full boost before I get the sled moving, I bury the tires.
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Just for fun:
Only 16 horsepower!
It wouldn't have been a bogus demonstration if it had been 2 Teslas of equal weight with different tires.
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However, does one horsepower equal one horse? Not quite. It’s a common misconception that one horsepower is equal to the peak power production of a horse, which is capable of a maximum of around 14.9 horsepower. By comparison, a human being is capable of approximately five horsepower at peak power production.
Instead, Watt designated horsepower to be equivalent to the amount of power that a horse can sustain for an extended period of time. However, there are many different variations of horsepower. https://en.wikipedia.org/wiki/Horsepower
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It was a joke. However, those draft horses can maintain that pull for a much longer stretch than was provided. They were hardly working at peak there. Since they average 1 ton each, that was about 16 tons worth of pulling muscle, plus the four people and the chariot in back (and probably a few hundred pounds of accessories).
Wanna bet they can destroy a Tesla?
I agree that a vehicle with more mass will generate a higher normal force and that as long as a vehicle isn't traction limited a vehicle generating more torque will produce more force than one producing less (it may not, however, be able to destroy that vehicle since that depends on the force differential).
As you're suggesting, more torque is better than less torque. A simple thought experiment illustrates this. If Vehicle 1 produces 600 NM of torque and the usable traction supports 600 NM of torque, and Vehicle 2 produces 100 NM of torque and the usable traction supports 600 NM of torque, then obviously Vehicle 1 will generate more force.
It's also axiomatic that more mass means more traction. Usable traction is defined as the coefficient of traction times the normal force. Since the normal force is simply mass times the gravitational constant, more mass means more traction.
However, the equation for usable traction shows that the coefficient of traction is as important as mass. A simple thought experiment illustrates this. Vehicle 1 and Vehicle 2 both sit on a perfectly slick surface which provides zero usable traction because the coefficient of traction is zero. Add 1000 pounds to Vehicle 2. Is there any more traction? Now change the tires on Vehicle 1 so that the tires puncture the surface, allowing usable torque to be generated by using the body of the opposing material rather then merely its surface. Will the wheel change allow Vehicle to have more usable traction? This thought experiment illustrates that while mass changes the normal force, since usable traction is the product of the normal force and the coefficient of friction, changing the coefficient can be more significant than the normal force. It also illustrates that a major factor, perhaps the major factor, in determining the coefficient of traction is the material composition of the two surfaces.
This is why adding 800 pounds of sandbags to the Toyota would not change the result on most any surface. On ice the studded tires should at least double the coefficient of traction for the Model S. On a dry road with standard tires the Model S will simply generate more torque which can be supported by usable traction. It's not that the Tesla Model S has more usable traction than the Toyota because it has more mass. In the video it has more usable traction because the coefficient of traction is greater with the studded tires. And if you reran the test on dry roads and had racing slicks on both cars, the Model S would still generate more force, not because its greater mass increased usable traction, but because it can produce more torque which can take advantage of the usable traction.
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OH NO, direct injection on the new Volts? That means the intake tracks and valves are due to get gunky with time, correct?
My '59 Morris 850 (before they were called Minis) sounded,,, like a stock 850 Mini....
On ice? Oh, I'll bet!
Or what about 16 Tesla X's? There hasn't been any discussion about traction control systems. Digital EV AWD is nearly impossible to beat by an "analog" ICE drivetrain. Formula 1 found this out many years ago when they realized they could pretty much take the driver out of the equation by telling them to floor it around the track and let the digital systems handle the rest.
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I get where you're going but we were talking about equal tires. Here's another thing a few of us northerners have a good deal of practical experience with in slippery conditions. High power-to-weight ratio makes it much easier to destroy (I use that term loosely - substantially diminish then?) tractive effort (My '85 Firebird was very good at doing this). On ice the torque of the Tesla (again with equal tires) could have caused it to spin its own wheels, and the Toyota, better able to manage its torque output could have dragged it around at that point.
If you watched Qinsp's video, he was managing Casper's torque output through that pull in an effort to control his tractive effort.
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