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QZRChedders t1_j1i5ivz wrote

An ICE engine has a torque curve that builds from idle up to peak usually 4-6 thousand RPM later. It takes time to find that torque and that power.

An electric motor is nearly opposite. The second you apply the voltage it’s off, maximum torque like a switch. That combined with multiple motors to keep each wheel working at peak performance and use that torque leads to ridiculously fast acceleration.

Similar reason big diesel wagons can punch so hard, they have torque low down and available but as they drop off (like electric motors) that’s where ICE is going to catch up if at all. I recommend looking at dyno graphs for a few cars and you’ll see this graphically.

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AverageJoe313 t1_j1ifo3a wrote

Internal combustion engine engine

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electricaldummy17 t1_j1jhlpi wrote

One could argue that if you were to just say "ICE", it may be over the head of eli5. I think ICE engine actually is a pretty quick way to remind someone at an eli5 level of what we are talking about and that it has an acronym.

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ADDeviant-again t1_j1jz537 wrote

That whole first sentence alone had 3-4 ELI5 terms and subjects in it.

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BOBALL00 t1_j1m74pn wrote

Electric doesn’t need to shift gears so your saving shift time too

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DreamArcher t1_j1ju6eo wrote

Max torque at zero RPM is only for AC induction motors (Tesla). Almost everybody else uses DC motors.

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Iphotoshopincats t1_j1i9g7c wrote

Been explained already but I wanted to have fun with this one

Superman (electric engine) and the in this universe the clearly faster flash ( combustion engine) are having a race by pushing an extremely heavy train along a track

Well for Superman the weight is not an issue he just has to make sure not to rip through the train while pushing so he just pushes on the back of train at maximum force that won't destroy and steadily accelerates.

Flash is there with the problem of he is faster but weight is a problem... But with enough speed he uses the kinetic energy of a kick to get the train moving, then another and another

With each kick the train moves faster and faster and more energy is converted into speed.

Flash train now moving faster than Superman's but took a lot longer to get there

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max_p0wer t1_j1i5pps wrote

Internal combustion engine horsepower numbers a little bit misleading. The numbers they tell you are actually "peak" horsepower. A 2022 Corvette makes peak 490 horsepower at 6,450rpm. This means it makes less horsepower at every other rpm, most notoriously at low rpm's.

An electric motor makes its peak power ALL the time.

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Red_AtNight t1_j1igtfx wrote

Not exactly. In a rotating engine, power is engine torque multiplied by rotations per minute. Electric motors don’t produce peak power at all engine speeds, because in order to do that, they’d have to produce peak torque at 1 rpm and then have the amount of torque produced gradually decrease as the engine speeds up.

What electric motors do is produce consistent torque at all engine speeds. They still have a power curve, it just looks a bit different than an ICE.

With an ICE, you only get peak torque at a certain engine speed, and you actually get less torque when the engine is going too fast.

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max_p0wer t1_j1itpka wrote

Do a google search for Tesla dyno graphs. You’ll see the power is virtually flat while the torque decreases steadily. It’s constant power output, not constant torque.

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A1phaBetaGamma t1_j1je8vl wrote

I think the person you're replying to is thinking of DC motors

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Cheben t1_j1igtpj wrote

They have basically constant torque (up to a point), but not power. Power output grow with rotational speed (power is torque times speed) , so the rated HP for electric vehicles can be extracted just before the torque drops of. A ICE also has low torque at low speeds, which is why they feel more sluggish to drive.

See here: https://images.cdn.circlesix.co/image/1/640/0/uploads/posts/2016/08/1682147d214d1e617551359320d2ee56.jpg

Electric peak power is at about 2900RPM there

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max_p0wer t1_j1ish12 wrote

Any “constant torque” would be due to the fact that at low speeds you’re traction limited so only a fraction of the cars power can be used.

Once you’re no longer traction limited, the torque will steadily decrease and power output will be flat.

This is a Tesla S P85D on a dyno. Notice the torque peaks (at 864 ft-lb!!!!) then steadily decreases. The power is nearly perfectly level just above 400hp for the entire second half of the run.

https://www.pinterest.com/pin/297096906643419592/

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RedditSchnitzel t1_j1iy7z6 wrote

Internal combustion engines basically have a very limited range of RPM where they can work. Too slow and they are going to stall and too high and the engine can't handle it.

That is why you have gears in your vehicle to allow your vehicle to drive different speeds but still having a small band of RPM for the engine.

With that understood, we can get to the main issue. An internal combustion engine doesn't produce a constant torque. You can understand the torque as basically the force with that the wheels try to move the car for this instance. Instead, the engine produces more torque the faster the engine is. That is why race car drivers try to shift right at the end of the gear and keep the engine hat high RPM.

Now, you don't want to do this with your own car, because is stresses the engine and has horrible fuel economy. The faster the engine spins, the more losses the motor has and the fuel economy gets worse.

That is where electric engines come into play. Modern electric car engines have the ability to produce a near constant torque with no connection to the RPM of the engine. So rather than having to spin up the engine first before you have the maximum force available, you have the force available even for small speeds then LOW RPMs.

This is why electric car engines can accelerate so high at small speeds compared to combustion engines.

​

Now, as a little caveat, this is not universal for all electric motors. Modern car engines use electronically controlled engines to have this effect. Especially for older train engines with limited electronical controls there are some variations and those characteristics might not hold.

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series_hybrid t1_j1iyyl1 wrote

Electric motors can make their max torque from the first RPM, and a gasoline motor needs to get up to its peak RPM's to make it's peak power. This is why an electric motor can be a one-speed, and gasoline engines need several gears to go through to stay near a higher RPM through most of the acceleration in order to accelerate reasonably fast.

Drag racing gasoline cars rev the motor up very high and then "dump" the clutch which makes the rear tires spin. If you do this is everyday life, the clutch will not last long.

With an electric, you can dump the full power into the motor for a few seconds without it overheating, or wearing out, so...they are built to be able to do that because it is one of the benefits of electric, so they want to emphasize it.

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citizenkane86 t1_j1jqe7m wrote

I’ve you’ve ever seen the cyber truck vs f150 tug of war videos this is the reason why the cyber truck will always win regardless of the power. When the driver of the cyber truck floors it the truck moves instantly, bulling the f150 backward, while the f150 will take a pause before it applies any force, and once it’s moving backwards it’s already lost. It’s more of a physics trick than a display of power.

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Muscular_carp t1_j1ij18u wrote

In absolute terms, they don't - both ICE and Electric vehicles are limited in acceleration performance by traction and tire technology at the top end. However, powerful small motors and instant torque do make it easier to build an electric car that accelerates quickly.

On the flipside, ICE cars have inherent advantages (mainly lower weight) in terms of top speed and especially handling, so electric cars that aim to be exciting tend to lean harder into the one thing they're especially good at comparatively and have developed a reputation for very good acceleration as a result.

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davidgrayPhotography t1_j1kpbna wrote

I could be wrong here because I'm not a car person, but I always thought it was because ICE cars need to pump fuel in and ignite it which takes time, whereas an electric car can just dump power into a motor and go,

But again, not a car person, just my naive guess.

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[deleted] t1_j1ig853 wrote

People are talking about the torque advantage of electric motors and while that does play into it, the superior performance potential of an EV is really about the power you can get out of small motors. Electric motors are far simpler to build. They're smaller and lighter for similar output than an internal combustion engine. So, you can pack more power into the car, and it goes faster.

Because an electric motor can handle faster revolutions than an internal combustion engine, you can also attach it to the wheels via a single speed transmission. So, while internal combustion cars are shifting, the EV is still just accelerating.

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Fred2718 t1_j1imt5s wrote

Was pitched a company doing add-on electric drive for F-150 pickups. They had a few dozen on the road, it Was not just vaporware.

The motor was claimed to make 400hp and was a cylinder roughly 14 inches long x 11 inches diameter. I did not verify this claim. I don't recall the torque spec.

But to be fair to both EV and ICE, you need to factor in the battery mass and volume, against gas tank mass and volume.

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