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by OnlineGladiator 2414 days ago
I am not arguing that an ICE vehicle is more efficient than an electric vehicle - I am saying that adding weight reduces efficiency for both. I was not making a general comparison between the pros and cons of electric vehicles, I was pointing out that one person's comment about better traction for electric vehicles was incredibly disingenuous because ICE vehicles can get the same benefit by simply adding weight - and they can also remove that weight when they want to unlike the electric vehicle.
3 comments

Your argument is incorrect as pointed out by dropin685 earlier. Additional weight by itself does not waste energy. It does require more power to accelerate. The extra power is turned into higher kinetic energy for the same cruising speed. However kinetic energy is not waste. It can be recovered during deacceleration. It's the lack of regeneration that causes ICE powered vehicles to waste energy, which doesn't apply to EVs with regeneration capabilities.
I am obviously failing to communicate as this was meant to be about the effects of weight and traction, and how batteries are not unique for adding weight to a vehicle (other than a lower center of gravity, but that has nothing to do with my original point).

While regenerative braking is most common in electric vehicles, this also is not unique to electric vehicles. A hybrid vehicle can just as easily benefit from this, such as the Prius.

> Additional weight by itself does not waste energy. It does require more power to accelerate. The extra power is turned into higher kinetic energy for the same cruising speed. However kinetic energy is not waste. It can be recovered during deacceleration.

This is incorrect unless the engine/motor, drivetrain, and tires are all 100% efficient - additional weight always wastes energy.

But I agree with you, electric vehicles are more energy efficient than gasoline vehicles.

> A hybrid vehicle can just as easily benefit from this, such as the Prius.

If you momentarily ignore the fact that its ultimate energy source is gasoline and focus only on the regen system a hybrid is an electric vehicle, just one that (sadly) lacks a plug.

> It's the lack of regeneration that causes ICE powered vehicles to waste energy,

Not just the lack of regen. ICEs waste energy while idling, as heat, noise, and vibration, and mechanical couplings like clutches and especially fluid couplings in automatic transmissions also waste energy. Automatic transmissions in particular are only 90% mechanically efficient, on top of all the losses from the ICE.

Good weight distribution in ICE cars is pretty exotic. Only fairly performance optimized ICE cars like a Porsche Cayman, BMW m3, and similar performance oriented cars get the ideal 50/50 distribution.

Changing that weight distribution is very expensive from a R&D perspective. Sometimes the battery is moved, or the engine is moved a few inches relative to the front axle. This is one of the reasons performance oriented cars are often rather large compared to their usable interior volumes.

Battery operated cars do have a weight penalty, but you can put that weight wherever you want. You could relatively trivially make a 50/50 distributor of significantly front or rear biased with no substantial R&D overhead or loss of efficiency.

For instance the Tesla model 3 not only has a very low center of gravity, but also a very low polar momentum. In an ice car that would require a mid engine design (like a Ferrari, Lamborghini, or the newest Corvette. While having an large usable volume, more like a bmw 5 series than a 3).

So basically weight distribution is easy to tweak with batteries, and even with the weight penalty have a substantial lead in efficiency.

I have already specifically mentioned that I am not talking about center of gravity or handling characteristics you'd find in a sports car. I have already written multiple comments about how you can put weight in a truck to add traction to the rear tires. I have already explained that electric vehicles are heavier but more efficient than ICE vehicles. You basically say similar things to what I said, and then come to the 100% wrong conclusion.

> So basically weight distribution is easy to tweak with batteries

No. You can do this when designing the car, but not afterwards. You want more weight in the regular pickup truck? Throw it in the back. You want less? Take it out. You can't take the batteries out of the electric vehicle. All my original comment said was you can add weight to the back of a pickup truck to improve traction on the rear axle. I didn't talk about center of gravity, or performance vehicles, or even mention that electric vehicles are heavier.

I am astounded by the amount of comments taking something I said, responding to it maybe tangentially and then concluding with "well that's why electric vehicles are better!" Let's just agree to disagree.

Yes, but on the converse side, the weight adds extra safety, at least with the Model X. Since it's heavier and the center of gravity is lower, they tend to not roll over very easily. https://cleantechnica.com/2019/02/14/why-the-tesla-model-x-e...
What I said:

> I was not making a general comparison between the pros and cons of electric vehicles

And you replied:

> Yes, but on the converse side...[something that has nothing to do with traction]

Am I unintentionally arguing that electric vehicles are bad? I get the impression people think I hate electric vehicles and are trying to convince me of their virtues, when I was simply pointing out what I thought was a logical flaw from another commenter.