most range efficient wheels for M3P

[mpgxsvcd]

Respectfully, Physics and Tesla disagrees with you.
An object in motion takes no energy to remain in motion. The only thing slowing down the heavy wheelset is aero drag, and the energy loss in the deformation of the tire. Ironically, heavier tires deform less and thus have less energy loss. Which is why trains with steel wheels that weigh 800lbs are some of the most efficient "tires" out there.

Tesla focuses a ton on aero, yet their wheels are quite heavy. If you were correct, they would spend their money on making the wheel lighter instead of adding mass and money to it with aero caps.

@gearchruncher is 100% correct here. Weight does not make a significant difference for steady state driving at highway speeds on flat ground. Aerodynamics and rolling resistance would be the significant factors there.

Here is just one example where it shows how little affect weight has at steady state.

 

[bhsf]

Respectfully, Physics and Tesla disagrees with you.
An object in motion takes no energy to remain in motion. The only thing slowing down the heavy wheelset is aero drag, and the energy loss in the deformation of the tire.

Have you heard of this thing called the coefficient of friction?

 

[gearchruncher]

Have you heard of this thing called the coefficient of friction?

Have you noticed that a tire does not slide along the pavement, it rolls, and no part of the tire in contact with the ground moves relative to the ground?

 

[bhsf]

Have you noticed that a tire does not slide along the pavement, it rolls, and no part of the tire in contact with the ground moves relative to the ground?

Good you know it rolls. Now what is the formula to calculate rolling resistance? Hint, it involves mass.

 

[Zoomit]

Good you know it rolls. Now what is the formula to calculate rolling resistance? Hint, it involves mass.

Let us please not debate that a heavy wheel decreases highway range. Yes it does, but it's effect is so insignificant that it doesn't matter.

Frr = Crr * N = Crr * M * g

N is the normal force due to gravity and mass of the car.

Increasing each wheel mass by 5 lbm, as an example, only increases the car mass by 20 lbm or 0.5% for a 4000 lbm car. That increases rolling resistance by 0.5%.

But the rolling resistance of a car traveling at constant highway speed is only responsible for about a quarter of the energy usage. The far majority of the energy is used to counter aerodynamic drag.

So a 5 lbm heavier wheel only increases energy expenditure, and decreases range, by 0.125% on the highway using reasonable simplifying assumptions.

That's about 30x less effect than the aerodynamics of the wheel. (An 18" Aero wheel is about 4% more efficient with aero cap installed than without.)

 

[White_Walker]

Anyone else here feel a little bit smarter and also dumberer at the same time reading this? ;-)

 

[gearchruncher]

Heavy tires require more energy to get to speed and to keep in constant motion.

The only thing slowing down the heavy wheelset is aero drag, and the energy loss in the deformation of the tire. Ironically, heavier tires deform less and thus have less energy loss. Which is why trains with steel wheels that weigh 800lbs are some of the most efficient "tires" out there.

Good you know it rolls. Now what is the formula to calculate rolling resistance? Hint, it involves mass.

Yeah. You might want to read what I actually wrote, and what the original quote was, and realize that not all tires are the same, so if the thing you changed on a car is the tire, then everything is out the window. Thus, you cannot universally say that a heavier tire increases rolling resistance because the exact same thing that makes it heavier can reduce the rolling coefficient as well.

 

[bhsf]

Let us please not debate that a heavy wheel decreases highway range. Yes it does, but it's effect is so insignificant that it doesn't matter.

I am not debating any of that. I am responding to two very inaccurate claims below.

An object in motion takes no energy to remain in motion. The only thing slowing down the heavy wheelset is aero drag, and the energy loss in the deformation of the tire.

 

[gearchruncher]

I am not debating any of that. I am responding to two very inaccurate claims below.

Then please, since aero and deformation are VERY INNACURATE reasons that show down the wheelset...
Give us exactly what does slow down the wheels, and why heavier wheels take more energy to maintain a constant speed since aero and tire deformation is not that.

I'll give you a hint, you can start here: Rolling resistance - Wikipedia