Just like ICE cars are limited by fuel economy, these EV cars should be limited by how much energy they consume.
EV EPA Calculated Numbers
- Thread starter Danno
- Start date
Just because you increase performance doesn't mean you decrease efficiency. I'm sure there is SOME correlation, as lower performance parts weigh less (thinner cables, wimpier cooling systems, smaller drivetrain components, etc) and removing weight improves efficiency, but most of those fat cables and heavy duty cooling systems are also used for the fastest possible DC fast charging... and nobody wants a slower charging EV, I can tell you that.
A base RWD Tesla Model 3 gets similar miles/kwh to my Bolt, if both are driven normally, at least according to a quick Google search. Now, in winter months, even a Model 3 Performance probably gets better miles/kwh than the Bolt, as the Bolt's resistive heater sucks up juice big time.
In my AWD Prologue I get HORRIBLE efficiency on the highway. It's got 288hp. The Model Y base AWD version has over 100hp more power. And you know what? I bet the Tesla gets the same or better miles/kwh because they put more effort into efficiency and it's aerodynamically way better.
In conclusion, since you have to build a big enough battery for good highway range, one or more beefy motors to make it quick enough to merge onto the highway, put in an advanced cooling/heating system to keep the battery and the cabin at the right temps whether it's -20 or 120F out and to enable 350kw DC fast charging for 30 minutes, you may as well just make the darn thing go 0-60 in 2 seconds. Price to build it won't go up much, but you can definitely sell it for more money and make more profit in the process!
Now, I think the updated Ultium based Bolt that's coming next year is going to be a hit for people that just want a cheap, utilitarian, compact EV. That's what the Bolt is... but the prior gen Bolt has some major limitations. A, slow DC fast charging (it maxes out at 55kw), and resistive heating (heat pumps are so much more efficient). The Ultium Bolt will solve both these problems, and assuming they can get the price down far enough below the Equinox EV, it will be a HOT seller for people that want basic, cheap, transportation.
Oh I get it, a more efficient system uses less power. 100% true. It all has to do with application, weight, etc. aerodynamics are another discussion. But, more powerful DC motors do require more energy, there is no way around it.
there is no difference in the power required to accelerate a 4000 lbs vehicle to highway speed, whether it be ICE or electric.
My overall point was, you do not need a 1000hp electric motor. That motor requires more power than a 200 hp motor.
Right, and I am mostly in agreement with you, but if you are driving normally, it takes the same amount of power to accelerate the car from a red light before the on ramp to highway speeds for merging, whether the car can do it in 2 seconds or 20 seconds. Now, there is surely some efficiency lost if you floor it and take advantage of all the power, but if you do it at a reasonable speed that matches the flow of what other drivers are doing (let's say you do it in 10 seconds), whether your car has 200000hp or 200hp, you just used pretty much the same amount of juice.
+1 Agreed! That'll get some people all bend outta shape.
A 1000 hp electric motor does not (I would think) have only 2 power consumption modes - zero or full power. If only 100 hp was being called for by the driver, are both a 1000 hp and a 200 hp motor going to provide that 100 hp with equal input wattage to the motor?
And - just because two vehicle may weigh 4000 lbs (and hence have the same intertia) doesn't mean they have the same rolling resistance, drivetrain friction losses, etc.
OVERKILL
$100 Site Donor 2021
It takes a given amount of HP (or watts) to move a given amount of weight at a given speed, with the same aerodynamics. There's really not any meaningful efficiency penalty in using a 1000HP electric motor to make 20HP or using a 200HP electric motor to make that same 20HP, because of how efficient electric motors are.
This is quite unlike the gasoline space where a large power dense engine operated outside it's peak BSFC range will be significantly worse on fuel than a smaller engine designed for high levels of efficiency in regular driving with considerably less peak power. This also correlates with the use of CVT's, which the use of is predicated on the idea of keeping the engine in its most efficient operating range. For example, the Pentastar uses considerably less fuel to propel a Grand Cherokee at highway speed than the 6.4L or 6.2L SC engines, despite all examples moving the same vehicle with roughly the same weight and the same aerodynamics.
This is why the HP war with EV's has been so wild, because you have an almost unlimited power ceiling with very little impact on efficiency. The key issues are, as @dogememe noted, related to the battery, and these same issues impact charging just as much as they do performance, if not moreso. So if you are already spec'ing the battery cooling and cabling for high speed charging, that same cabling and cooling enables an obscene amount of current delivery to the motors by default.
so the input to each motor.....1000hp or 100hp would be the same, with the same range?
OVERKILL
$100 Site Donor 2021
Pretty much. It's PWM, so the motor only produces as much power (watts/HP) as required to achieve what is being commanded, so for a static land speed that requires say 20HP, the peak capability of the motor doesn't matter, since it is only being pulsed enough to produce 20HP and that ultimately is what dictates the draw on the battery.
Sure, but would that be the case in practical application? I argue not.
I think we are going into left field here and away from what I was saying.
What I am saying is that the higher power motor uses more power and in practical application, would be built such that the rest of the systems would be able to accommodate the higher power.....
The lower power system would be built to accomodate the lower power.
And as we all know, higher power stuff, motors, cabling, frame, tires etc, need to be built to a higher standard=most costly=less efficient.
What would happen if you installed a 1000 hp motor where a 100 hp motor is supposed to go.....and attempted full load.........nothing good.......
I do not know how that is misunderstood.
OVERKILL
$100 Site Donor 2021
Respectfully, I don't think we are. Electric motors are insanely efficient, there simply aren't the losses you are assuming there are.
But it doesn't meaningfully use more energy, that's the point. I've given several examples now of why that's the case. Yes, a 1000HP electric motor will draw more current; will use more kWh than an 100HP electric motor when at full power, by 10x, but during normal use, when you aren't using peak power, they use basically the same amount of energy.
But the same has to be done, for much of this stuff, such as the battery and cooling system, for high speed charging. So it's being done anyway, the ability to handle high rates of DISCHARGE is almost incidental in being able to handle high rates of CHARGE. The exception would be the motor cabling, but compared to the rest of the system, that's not overly significant.
Yes, structurally, a 1,000HP EV is going to have a more robust chassis, but you can see that in application this really doesn't matter. The Tesla Model S Plaid isn't paying a huge weight penalty over the lowest spec version, same with the Model 3 and Y.
The Model Y Long Range weighs: 4,363lbs
The Model Y Performance weighs: 4,398lbs
The Model Y Standard Range RWD weighs: 4,208lbs
So even with a considerably (62kWh vs 82kWh) smaller battery and one less motor, the difference between the top-spec Model Y and the lowest spec is only 190lbs.
But that's not efficiency. A 1,000HP electric motor isn't less efficient than a 100HP electric motor.
The chassis still has to be strong enough to be crash worthy and provide occupant safety. A Dodge Charger Demon isn't massively structurally upgraded; the car isn't massively heavier, than the plane-Jane version with the 300HP Pentastar. Yes, some parts will need to be heavier duty for the higher specific output versions, but it doesn't have a considerable impact on the overall efficiency of the vehicle in the context of EV's.
One thing that DOES matter is tires. The higher performance EV's generally have stickier and wider tires, and this has an impact on highway range.
You don’t need 1000hp for sure. The power is a byproduct of a large battery for range and fast power transfer for quicker charging. Limiting the power won’t do anything for range unless someone is constantly using full throttle. Plenty do limit it. Tesla does not with their higher end models. The only reason my Model Y Performance has lower range than the Long Range is the bigger wheels and tires. The programming for more power has nothing to do with it. In fact you can match the range by putting the same wheels and tires on it from the Long Range model.
Which was more to my point.
Flooring it...... 50% throttle and so forth. Real driving, stop and go, etc.
1000hp motor uses more power than a 1000 hp motor.....but no no no.......all the experts on here want to nickel and dime the whole comparison.
Most people who have EVs live in a city. Sure on a highway stretch you have light throttle input, but who does that all the time.
The faster the weight is moved the more power consumed. 30% throttle on a 1000hp engine is 300hp no matter how you cut it.
That is the difference between scientific observation, facts, and practical application......they all tell the truth and they all lie at the same time.
No but in practical american driving, it uses more power. I was never really speaking on "efficiency" I was speaking on power used from power available. Of course there is a difference.
Tankless water heaters are much more efficient, but if someone buys a tankless water to lower their power bill.......they have been greatly misinformed.
No it is not a byproduct. Not at all.
It is a powerful electric motor with the cabling between the motor and battery to flow enough current for 1000hp. It is designed for that. The larger the AH the battery the longer it lasts between charges. Voltage does not change.
In practical american driving it does not. You can't drive an electric vehicle "wide open" on city streets. At least, not for long. If you are a good driver you go with the flow, which means not accelerating faster or slower than the traffic around you. So, putting a 200 HP motor in place of a 1,000 HP motor accomplishes nothing. The majority of the wire/cable must remain as is in order to charge the battery at an acceptable rate.
A less powerful motor accomplishes nothing.
If you live in an area with a lot of traffic like I do, you are unfortunately limited in the amount of opportunities to apply gonzo power. Then there's going through the neighborhood, I never speed in my neighborhood, and I live in the very back. This leads to better efficiency with our EVs whether you want to or not.
I posted a screenshot of efficiency in another thread of a 6 mile round trip drive to my pharmacy's drive through and back to my house, where I made 3.6 miles/kwh. This is the best I have done with my Lightning, efficiency wise. My old Navigator almost certainly would have gotten 12 mpg on this trip, especially if I left it running while waiting in line at the pharmacy drive through, which I did with the Lightning as it was cold and I was running the heater.
A less powerful motor costs less to the manufacturer and the end user. I don't know what the delta is though.
OVERKILL
$100 Site Donor 2021
Precisely the point I've been making, thank you for reinforcing it.
Yes it absolutely is. The motor in most cases isn’t even different between models. For the ones that it is the weight itself is usually negligible. It’s not more power hungry. It’s just the motor’s ability to take the available power and turn it into rotational force. Some manufacturers that don’t want the vehicle to be a performance model just limit throttle output. Some of those still have terrible range because they don’t have the larger faster charging and discharging batteries to do so. Look at the Lucid models. They have some of the best ranges and insane speed and power by exercising efficiencies in aerodynamics. You could limit it to 300hp and it wouldn’t matter if you didn’t take the more aggressive wheels and tires and heavier brakes away from it. Losing one of the motors to forfeit AWD can help if you’re trying to save weight, but that’s not a solution if you live in an area with adverse weather. Even then that may afford you 5% more range with many models. The motor itself is a much smaller factor than you’re trying to claim.
