quote: Instant torque - irrelevant, since the engine produces no horsepower when it's not turning and it produces low horsepower when it is turning at low RPM. A gasoline engine also has "instant torque" as it is already idling at 800 RPM or so, and it has "instant horsepower" as well.
quote: Ridiculous performance - it is quite ridiculous, since driving it in conditions that do not have california-like weather will result in severely compromised run times.
quote: Long ev range - the energy density of batteries is nowhere near that of gasoline or diesel, and it is unlikely to be anytime soon.
quote: False. Torque accelerates a car; the heavier a car is, the more torque you need to reach a certain speed by a certain time. ICE engines do not produce "instant torque". When the OP says "instant torque", he/she means the tendency of electric engines to produce 100% of the torque at all RPMs. ICE engines don't do that; generally, ICE torque is 50% of the max at the lowest RPMs (generally 800-1,200) , peaks around 2,000-3,500, then drops to below 50% from 6,000 and beyond. The swing from 50%-100%-50% is what jerks the car during gear shifts up and pushes you back in the seat as you hold the gas.
quote: Electric vehicles, producing 100% of the torque all of the time, generally lack the jerking and push back. Drivers have commented on how deceptive acceleration is in EVs since it's there, but you don't feel it. "Instant torque" makes acceleration smooth, something you can appreciate in a heavy vehicle.
quote: The Model X isn't even in production yet. Wait until there are models on the road with recorded data before making these kinds of claims.
quote: BTW, the OP meant the 4.4secs it's estimated to get to 60mph. That's better than many sports cars, and is comparable to some older supercars. Not bad for a car weighing more than 2,100kgs (that kind of performance is usually seen from a car weighing 1,400kgs with that amount of HP and a better aerodynamic drag coefficient).
quote: Which is why the OP said long EV range, as in "long for an EV." We have to see a real car in action, but the estimates are pretty good for a battery-only EV. Which invalidates the rest of your post, since Telsa doesn't create cars with gasoline generators.
quote: Considering your posts in this article, it's clear that you're not only woefully ignorant of this topic you're also fond of rambling and attacking people who don't agree with you.
quote: If there is anyone who is reading this thread and would like to know why everyone else disagrees with Eric's comments (or finds them not worth reading) I would be more than happy to explain in greater detail. There's no point it explaining it to him since he's spouting nonsense that can be debunked by an introductory book on automotive concepts and physics.
quote: News flash, people use quick acceleration a lot more often than they drive at 125mph+
quote: Nobody cares about top speed in a full size sedan.
quote: Oh nice argument. Great supporting evidence too.
quote: Well then I declare that "nobody" cares about acceleration in a full size sedan.
quote: People don't buy Tesla's because it's a performance car. Get a clue. If it drove like a dump truck, Elon Musk would still be a hero.
quote: It's great that electric motors give you "max torque" and all that, but I don't know why EV proponents go on and on about it so much. People simply don't drive like that in real life, even if they can.
quote: an electric engine will have better performance in most real world situations and will feel like the premium engine.
quote: Go drive a Leaf, I don't see people accrediting that with a "premium" feel in ANY area.
quote: For nearly $100k it damn sure better feel like a premium engine.
quote: But not even I go around launching my car for the best 0-60 times possible, and I don't see anyone else doing it either in normal driving.
quote: Having said that, I find pretty much all of Eric's posts here embarrassing. And that's coming from ME lol.
quote: How much nonsense can you cram into one post?
quote: "Instant" refers to zero lag when you press on the pedal. You may think there's none on a gas car, but that's because you don't know what zero lag feels like.
quote: The peak power from a gas engine at cruising RPM (for any speed) will pale in comparison to Tesla's induction motor at the same speed. Gas can only compete when you downshift and rev the engine up.
quote: A Model X will have ridiculous performance under all conditions. It faces no performance decline at altitude, like a gas SUV.
quote: Your understanding of a PHEV is pathetic. You don't use the engine to fully charge the battery. You use it to power the car when the battery runs out. Your numbers are complete BS as well, as they imply 10% thermal efficiency for the engine.
quote: 61% of US electricity comes from nuclear, natural gas, and renewables, all of which are far cleaner than gasoline. More importantly, virtually all US electricity is generated away from populations centers, using domestic fuel, at a fraction of the cost per mile, for all ~15 years of a car's life.
quote: REALLY? So the fact that electric motors' torque declines sharply as RPM increases is better than a gas engine, whose torque curve remains relatively flat as RPM increases, only to decrease gradually near the redline.
quote: Actually no. During the current limiting phase of the electric motor acceleration (zero RPM to peak power) the electric motor will produce pretty much constant torque due to constant current. When the motor reaches peak power it goes into the voltage limited phase where the back EMF of the motor limits the current and available torque goes into gradual decline.
quote: Current limits and battery voltage are not set in stone but are chosen by design for reasons like extending battery life.
quote: ICE's have zero torque available at zero RPM and therefore must idle. To get a car moving some slippage has to occur either by clutch or torque converter. An ICE's torque curve is far from flat anywhere in the RPM range.
quote: Back EMF does not limit current, it represents an increase in voltage that will rise until it matches the input voltage.
quote: With the Tesla, you could easily find yourself out of batteries after doing a few 0-60 sprints "for fun" at full throttle.
quote: Torque converter are viscous couplings and do not "slip".
quote: I don't know if it was true that he was just quoting wikipedia, but back EMF does indirectly limit current. You are correct about the current limit due to wire heating, but that's at low RPM. At higher RPM, there's a power limit due to battery/electronics/cooling, so V*I*pf is roughly constant, and voltage goes up while current (and torque) goes down with RPM. At even higher RPM, you hit a voltage limit from wire insulation and/or IGBT limits. So now you can't keep V*I constant, and ever increasing back-EMF with RPM limits current even faster.
quote: If by "a few" you mean "hundreds", then sure.0-114mph sprint, and cruising back to zero. 1 mile travelled, 0.5kWh used. So even with a leadfoot, you can cover 150+ miles on a charge.
quote: "Slip" is defined as the difference in rotation speed between input and output. Yes, viscous couplings have non-zero slip.
quote: You say no, and then basically say what I just said followed by something you paraphrased from wikipedia in an attempt to seem smart but likely don't understand.
quote: Voltage determines the speed of the engine; the current drawn will rise if a load is placed on the motor (which causes a drop in voltage). Current itself is limited by system wiring and the motor's windings, and exceeding this current would cause the motor and/or wiring to overheat.Will be funny to see what happens if a Tesla motor stalls while stuck at "full throttle". It will basically weld itself into a clump of molten metal in seconds.
quote: I'm not paraphrasing anybody!! Because your statement implieded that torque drops off (sharply) from zero RPM I stand by my disagreement with that.
quote: You might know the electrical theory but you don’t know how EV’s work. The motor controller will limit the current available to the motor. At low motor RPM it will chop the voltage to ensure that the current doesn’t exceed its preset limit. This is what I call the current limited phase. As the current available is the preset limit it is constant as is available torque. It’s the motor controller that limits the current not the load. Of course that is semantics as the load will increase to match the current i.e. the car will accelerate there by loading up the motor. As the motor crosses peak power (maximum voltage, maximum current) the back EMF generated by the motor is sufficient to prevent the current from exceeding the preset limit of the controller.
quote: The point is that electric motors' having full torque from 0 RPM is not an advantage over the gas engine. Sure, it makes the car "feel" fast but the performance figures tell the full story, and they're not exactly shattering any records.
quote: Current itself is not what drives the motor, it is VOLTAGE that makes things move. Voltage must be high enough to overcome the resistance of the system, and when a load is placed on the motor, resistance increases and voltage drops. To maintain a speed at a given voltage, more current is drawn by the motor.
quote: So the fact that electric motors' torque declines sharply as RPM increases is better than a gas engine
quote: The tesla has a 85 kW/h battery and your typical gas powered generator at full load uses about 1 gallon of gas per hour, per 5 kW of output.
quote: So if you had a 20 kW generator you'd have to run it for 4 hours to fully charge the 85 kW/h battery, which means 16 gallons of gas.
quote: Last I checked, 16 gallons to go 30 miles is a paltry 1 MPG.
quote: What you and other morons don't seem to get is that charging batteries IS AMONG THE MOST INEFFICIENT USES OF ENERGY possible.
quote: Of course it is. For engines with the same peak power, constant power with declining torque is far more useful than flattish torque and rising power.
quote: WTF is "typical"? Some POS from Home Depot? That's not where automakers get their engines, genius. Once again, you're using a 15% efficient engine for no reason.
quote: What on earth makes you think a car needs 85kWh to travel 30 miles? The Tesla does well over 200 with that much energy, even under bad conditions.
quote: Once again, no PHEV charges up the battery with the generator. The electricity drives the wheels, and only a trickle goes in to balance the occasional battery draw.
quote: WTF are you talking about? Round trip efficiency for lithium ion is 90% efficient.
quote: Seriously, where on earth are you getting all this nonsense from? Is there some website polluting your mind?
quote: Tesla knows how to take advantage of the electric drivetrain to the fullest. Along with the advantages you mention, the Model X will have an unparalleled center of gravity for an SUV, gobs more room than a Cayenne/X5/X6/Q7 due to the frunk and lack of a drivetrain tunnel, and save $2k+/yr in gas.
quote: It's going to set a new bar for luxury/sport SUVs.
quote: A tesla with an 85 kW/h battery can get you about 30 miles in "real world conditions", and that's likely on the high side...but let's say it is.
quote: Sets a new bar for failure.
quote: 250 full charges at $12.75 per charge is $3,187.50.Nice job. You avoided paying $2K/yr in gas so you could pay $3.2K per year in increased electrical bills.
quote: From your link that you obviously didn't read:The total range -- adding the unused 4 miles, would be 238. Yes, 238 is 11 percent short of 265. Moreover, it was done while being very stingy with performance (for the most part). Is that 265 actually valid? If you drive predominately at highway speeds, then probably not. But were we to have included more medium-speed roads (long stretches at 45-50 mph) well, possibly.
quote: Why do you keep saying this? I could go on and on. Nobody has ever got only 30 miles on a full charge in a Model S.
quote: 250 full charges? That's at least 50,000 miles on a Model S. Using your own 15 MPG figure for the SUV, that's $13,333 in gas to go the same distance.
quote: It's hilarious that you're completely oblivious to how dumb you made yourself look with your posts here.
quote: You link to a best-case scenario test, where the car is driven at relatively low speeds constantly to see what the maximum possible range could be.
quote: I was planning to drive fast, from 70 to 75 mph along the Interstates that made up most of the route. The terrain was hilly. There would be a prevailing headwind. And the advancing fall season promised cooler temperatures.All of these factors would eat into range.
quote: 50K miles? LOLOL wow, too much stupid contained here.
quote: Really? You're still defending your laughable claim of 30 miles range from 85kWh? In what way does anything you quoted suggest that? It'll fall to 240, maybe 220 miles, not 30.
quote: Learn how to read. They got 234 miles WITHOUT much 50-mph driving. It was mostly highway, "cruise control set at 65 mph". They were talking about how to achieve 265 in your quote.
quote: And why did you ignore the second link?
quote: Even then, 168 miles from less than 50kWh. That's over 9x the efficiency of your BS claim.
quote: Figures you'd say that, given that you have the math skills of a 2 year old.
quote: Let me break it down for you: 250 full charges * 200 miles at least per full charge (well below the 265 mile rating and every real world test out there) equals 50,000 miles.
quote: Even Reclaimer, who doesn't agree with me on anything, agrees that you're embarrassingly wrong.
quote: Eric, you claim to not like MotorTrend, yet you looked only at that link when I gave you another one of someone who drove 168 miles at 70-75 mph in real world hilly areas using 50kWh of electricity. That's 3.3 miles per kWh.
quote: You claim 30 miles using 85 kWh, i.e. 0.35 miles per kWh. That's one ninth real world measurements.
quote: Even if you were right about slower speed, why don't you explain to me what physics justify a 9x difference in efficiency? Tesla's website notes 55mph for their 300 mile range figure, not 265 or 234. 65-80mph does not need 10x the energy of 55mph, you halfwit.
quote: Misuse the word efficiency? Do I need to link you to the dictionary now? How is miles per kWh not a measure of efficiency?
quote: The battery is temperature controlled, so there is no range degradation from road heat or surrounding vehicles LOL.
quote: You picked a fight with the wrong guy. I'm a Caltech electrical engineering PhD, and my work was even featured in an article here on DT. You clearly are just some poser with no real understanding of engineering or math.
quote: I give links because my facts are based on data. Yours are based on nonsense you conjure in that useless head of yours with no basis in reality.
quote: You're a complete dunce. I won't waste any more time on you.
quote: This is pretty funny because you fail to acknowledge the fact that air resistance increases exponentially with speed. If you only needed 20 HP to keep the car moving at 60 MPH, and you wanted to go 80 MPH, you would need ~40 HP. You're effectively doubling the power required for only a modest increase in speed due to the way air resistance scales.
quote: While you may be saying "that's not 10x", because you are stupid and fail to accept the fact that as load on batteries increases their AVAILABLE capacity falls. Which means that cruising at 55 MPH may yield a full 85 kW/h worth of power from the batteries, however more than doubling the power drawn by going just 75 MPH means your effective capacity will fall by several kW/h - i.e. the battery depletes at a faster rate.
quote: Aerodynamic drag only makes up about half of the total resistance at 60 MPH in most vehicles with the rest coming from rolling resistance so by my calculation going from 60 to 80 MPH should consume about 39% more power or from 20 HP at 60 MPH to 28 at 80. Considering the Tesla’s very low coefficient of aerodynamic drag and weight it is likely to be less than half of total resistance at 60 MPH making the HP requirement at 80 some what less than 28.
quote: Lithium batteries don't have the high internal impedance of some of the older chemistries. In fact some lithium chemistries have 1/40,000 the internal impedance of lead acid AGM’s for instance. Kokam quoted a 97% charge recovery at 0.3C charge discharge rate for some of their cells.
quote: Available capacity won’t decline by anywhere near as much as you imagine. Even in the most demanding condition of say successive sprints to 60 MPH.
quote: Initial power demand from stand still would be very low and would rise linearly up to peak power before going into decline. Considering the Tesla’s top speed it might not even see peak power before it reaches 60 MPH.
quote: If we say it does then average draw would be around half of peak. At peak power we would be talking about a 3C discharge rate so on average about 1.5C in the sprint.
quote: I know there are some big flaws in the derivation but in the absence of some better figures it gives an idea of what sort of numbers we are talking about. At a normal cruse of say 60 MPH the discharge rate would be less than 0.2C and at 80 it would still be less than 0.25C.
quote: This is incorrect. As per my example, which is an EXAMPLE to illustrate the exponential increase in air resistance vs speed, if you know how much power it takes to move at a certain speed then you are already accounting for the coefficient of drag. The increase in power would be about the same percentage-wise regardless of the CD, the only difference being that a lower CD would mean less power for a given speed. So your calculation of a 39% power increase is off by a lot.The model S is not light by any stretch of the imagination; it's a 2-ton porker of a car. Granted there are other luxury sedans tipping the scale near or north of 4,000 lbs - Audi A5 comes to mind - but the Audi has an AWD system which the tesla does not.
quote: Tesla uses lithium ion batteries, not the more powerful (and lighter) lithium polymer, likely due to the latter being even less stable than the former, and for that particular battery type 4C is pretty much the upper threshold of discharge that you'd want to subject the cells to.
quote: You're missing a key point that you yourself were quick to point out in your first response - electric motors have full torque from 0 RPM. While a motor at 0 RPM is not producing any power, that does not mean it is not consuming energy. When you floor the accelerator in an electric car, the load will be at or near the full capacity of the system.In the case of the tesla, that means 850+ amps will be drawn from the battery under full throttle, from start and this will taper off as the car slows its acceleration.
quote: No, not really. There relationship between output power and input power is quite rigid. You cannot draw less power from the battery and have the motor put out its full rated 310 kW of power. For the motor to put out 310 kW, it will draw MORE than 310 kW from the inverter, which draws from the battery...this works out to about 4C as explained above.
quote: While the motor is drawing full power from the battery and the car is at a stop, that is 0% efficiency.
quote: The reality of the situation is that right now electric cars are expensive and inferior to their gasoline counterparts.
quote: When characterizing a vehicles drag you cannot disregard the vehicles rolling resistance
quote: You misunderstood my reference to the model S weight. Because the car is heavy and has a low Cd I thought rolling resistance would make up a much larger portion of total drag at 60 MPH.
quote: Total power consumed at 55MPH according to Tesla’s figures is 14.6 kW so if we assume the remainder is solely due to rolling resistance Prr=8.9kW. If we assumed 85% efficiency in the drive...
quote: Gasoline contains about 33.6 kWh per gallon. That means the Tesla pack contain the energy equivalent of 2.5 gallons of gasoline. Any way you look at it it is very efficient at converting that energy to miles.
quote: The key parameter they need to stay below is the core temperature of the cells....Shallower thermal cycling should help cell longevity.
quote: The motor controller acts a bit like a transformer while the controller will always see full battery pack voltage on its input side it will chop the voltage on its output side and even when it is pushing its current limit on its output side its input current will be lower.
quote: It will not draw the full 850+ amps from the battery from the start. Initial amps on the battery side of the controller will be much lower.
quote: You’re talking peaks I’m talking averages. I’m saying that peak power won’t be drawn continuously.
quote: For about a millisecond. While an ICE is idling that is 0% efficient for much much longer. 0% efficiency at 0 RPM doesn’t tell us a lot about what power will be consumed at that point on the curve.
quote: Expensive yes I don't disagree, inferior or not depends on your use case, on what you are hoping to achieve.
quote: Drag is an aerodynamic effect; rolling resistance is a separate thing, and it's effects on the net friction that the vehicle must overcome to accelerate and move is not substantial. You are driving this conversation off topic by fixating on minutia.
quote: No, I didn't misunderstand you. The fact that the car is heavy contributes to its inefficiency. Rolling resistance is largely a factor of the tires - their width and their inflation pressure.
quote: You've already made two 'questionable' assumptions in an effort to make the numbers look "good" or seem right...but lets' examine this with your figures.
quote: Going by what you cite as Tesla's 14.6 kW (20 HP) figure to sustain 55 MPH, we can simply scale up the power required for higher speeds, because:Power:= Work/Time= Force x Distance/Time= Force x VelocityAir resistance is proportional to the square of the speed, and going from 55 to 80 MPH is a 25 MPH increase, or a 1.46 increase in velocity.We square 1.46 to get 2.13, which is the new force.
quote: 14.6 kW x 1.46 x 2.13 = 45.4 kWSo to drive your model S at 80 MPH using your 14.6 kW @ 55 MPH figure, it takes 45.4 kW or 60 HP - your results are off by quite a bit...at this rate your effective range will be around 150 miles, because remember, 45 kW of engine output will draw MORE than 45 kW from the batteries.Like I said before, if you know how much power it takes to go a certain speed, you can figure out how much more (or less) you would need for a change in velocity using some very basic math.
quote: Stepping up the voltage costs efficiency. I do not know what the operating voltage of the model S inverter happens to be, however I am well aware that it regulates its output voltage which is how it controls engine speed.
quote: When I launch a car, I rev the engine up to a specific RPM and drop the clutch. The engine will stay at or near the launch RPM and then increase. There is nothing that says I cannot launch the car AT the redline if my tires have enough traction, thus having the engine producing almost all of its power AND torque from a stop.
quote: The key point is that the batteries will be discharging at 850A or more when the drive program allows 'full power'...and it will be close to full power from a stop if you floor it and have the car in "performance mode".
quote: False. The idling engine is producing torque and therefore power. Simply because the car is not moving does not mean efficiency is 0%.
quote: 0% efficiency means that the electric motor is drawing current but not moving, and since it is not moving it is not producing power so efficiency is 0%. When the motor draws current and does not move, the energy radiates as heat. It is not a difficult concept to fathom, even though it is only for a brief moment.
quote: Tesla is trying to achieve an electric car that replaces gasoline cars, and that's just not happening. It takes too long to charge vs filling up with fuel, using the A/C can have a big impact on range, as can loading the car up with passengers and cargo. Reliability is also in question, and there are already plenty of reports from owners who have experienced problems like the car completely shutting off (while being driven) and being unable to start.
quote: Really, well all those poor fools buying low rolling resistance tires are just wasting their money then.
quote: The energy consumption of a vehicle virtually all comes back to two factors. Weight and aero drag. First you say weight will make a car inefficient then you totally disregard it in this calculation. So which is it, is weight in or is it out. Does weight generate a drag force which must be overcome or can we say its basically zero so we can just ignore it.
quote: A bit too basic unfortunately. It seems to have escaped your attention that aero drag scales with the cubic function of velocity when it comes to power requirements and including all the drag that doesn’t scale will dramatically exaggerate your figures.
quote: I told you exactly what the aero drag power requirements were at 55 MPH yet you choose to ignore that and generate more nonsense. If I apply a bit of reducto ad absurdum to your argument that all drag is aero drag and therefore scales to the square function of velocity then at zero velocity the car would exist in a frictionless state with only its inertia to resist motion if on a level surface. You would have no trouble pushing a 4700lb car with your pinky finger. It only takes a small force and a bit of time to overcome inertia.
quote: Actually I’ve been trying to tell you that it regulates its output amperage and it controls motor torque not speed. EV’s would be hard to drive if the motor controller and accelerator position regulated motor speed.
quote: EV’s don’t work that way. The power provided at a full throttle launch will ramp from some initial value required to overcome losses up to peak power at peak power RPM and speed.
quote: Wrong. Peak amps is only drawn from the battery at peak power. Peak power occurs around 7000RPM. Peak torque is a band from 0 to7000 RPM. 7000 RPM by my calculation would occur around 57 MPH. Don't forget EV's control torque. You don't get "full power" but full torque when you floor it.
quote: And that idling torque is totally consumed internally overcoming pumping losses and bearing friction.
quote: Actually I was thinking more about what their customers were hoping to achieve. Personally I would like to get off blood oil.
quote: I didn't disregard weight.
quote: Weight has already been accounted for by the baseline value, which I scaled.
quote: It's really very simple and I'll repeat it for you: if we know how much power it takes for a vehicle to move at a certain speed on a level surface, we can use a simple scaling formula to ascertain the power required at higher or lower speeds.
quote: False. The primary resisting force is aerodynamic drag. Again, your fixation on minutia in an effort to obfuscate the real point only makes you look like someone who can't accept that they were wrong.
quote: Verbal diarrhea is not the mark of someone who knows what they're talking about. You seem to be sliding into a pit of repetition peppered with stupidity. Next thing we'll have you telling us that climate change affects the Tesla's efficiency because vegetable.
quote: That's incorrect. It uses a PWM type of speed control, which limits voltage. Current limiting is an automatic result of pulsing the drive voltage at lower frequencies when the car is moving at lower speeds, and higher frequencies when the car is moving faster. The pwm system allows for "real time" feedback on what the engine is doing and allows its performance and response to be tuned.
quote: If you were to simply make a direct "always on" connection to the motor from the inverter, the car would probably have trouble gaining traction.
quote: FYI direct current limiting causes the excess current to be bled off as heat. That would be a very inefficient method of regulating the engine speed...and incidentally it's why tesla uses a PWM speed control. And yes, it's called a SPEED CONTROL not a torque control.
quote: I'm quite aware of the differences; but you've cleverly managed to miss my point yet again. The point I was making, is that while electric cars may have "full torque" from 0 RPM, launching a gasoline car from a stop can be done in such a way that you have nearly full power and torque from a stop. It's called launching for a reason.
quote: Since the inverter regulates the motor using a PWM type of system, full throttle doesn't equal a full-on connection between the motor and power source. The entire powerband is regulated, and that means the power is always pulsed, i.e. on and off.
quote: The problem with people like you is that you believe you know what you're talking about but don't. Do you think that the motor spinning at 7,000 RPM in free air (no load) will draw the same current as it would pushing the weight of the car down a drag strip (full load)?
quote: Please shut up about your idiotic and incorrect calculations and moronic theories about how electric motor drive systems work. You really do not know what you are talking about here and it's just getting tedious repeating myself.
quote: The amount of power consumed by the belt driven accessories is minimal at idle. Torque is not consumed; it is transferred.
quote: Oh yes you did. I for one happen to understand that zero squared is still zero.
quote: Yes but you than scale it with total disregard of weight solely as a function of speed.
quote: Repeating the same flawed argument over and over again doesn’t make it correct.
quote: I don’t accept I’m wrong because I’m not and I have proved it. Minutia it’s not. Have you ever tried to push a 4700lb vehicle?
quote: Who said anything about current limiting with an additional load? The Back EMF of the motor and the resistance of the windings can be used to control the current if you chop the voltage accordingly. I find it really hard to believe that you think you cannot control the torque output of a motor. Really?
quote: I didn’t miss the point. The point was redundant. Just because you can have full power and massive torque and convert your tires to smoke at launch doesn’t mean that EV’s must have full power available at launch. They don’t and they don’t need to unless the objective is to make lots of expensive smoke.
quote: When you get abusive do people pay more attention to what you say? Does it improve your credibility?
quote: When a system is in equilibrium, i.e. idling at a constant RPM, any torque produced by the engine must be matched by an equal and opposite torque or the engine would not be in a state of equilibrium and would either be accelerating or decelerating. When the drive is disengaged that torque will be predominantly internal losses. Physics 101. I’d be interested to hear your take on where that torque is being transferred to.
quote: If you are calculating the approximate power required for a car to move at a certain speed without knowing the power required to move at ANY speed in the first place, then weight would be part of that equation...but since we already knew how much power it takes to move the car at a given speed, weight has already been factored, and therefore we can scale power, as I did. Not sure how many times I have to repeat this until you get it.
quote: so get over it and learn some basic math while you're at it.
quote: quote:Minutia it’s not. Have you ever tried to push a 4700lb vehicle?
quote: Oh that's a new one - you restate things I've said and then try to present it as what you've been saying all along. LOL Nice job, but you are still not grasping the basic functions of an electric motor and its respective speed controller.
quote: In an EV we don't want to control the speed of the motor but the torque it puts out. If the accelerator position controlled speed the vehicle would be very difficult to drive. Hence the motor controller manipulates the current by manipulating the voltage but the voltage doesn't bear any direct relationship to the accelerator position. None of this is in disagreement with what you have said I’m just trying to add a different perspective. As for load when you encounter a hill the driver must adjust the accelerator pedal to maintain speed (as you currently do in your ICE powered car) increasing the current to maintain the voltage.
quote: Actually it's not redundant, because it completely shatters the whole "full torque from zero RPM" line that the ignorant EV humpers cite as a major benefit of electric motors over gasoline engines...apparently they don't know how to launch a gasoline car to maximize its acceleration and assume that all acceleration happens off-idle...and if you launch correctly your tires will hook and you will accelerate quite nicely.
quote: I'm hardly being abusive...maybe you're just too whiny and thin-skinned.
quote: You probably spent hours writing this statement, even soliciting your asian friends for help, only to end up "not getting it".Your previous statement attempted to portray the engine accessories as requiring all or most of the torque of the engine at idle - which is false. The power steering pump, the water pump, alternator and A/C unit combined place a relatively minor parasitic load on the engine, whether it's idling or at its redline.Yes, I'm sure you thought you are brilliant for pointing out newton's 3rd law, but that is obvious that was never in question or in doubt.Torque is a force, so it is transferred rotationally along an axis. It is not "consumed". Power is consumed, and power is torque x RPM.
quote: An axle spinning at a certain RPM being driven with a fixed amount of torque can continue turning so long as the load placed on the axle does not exceed the amount of torque which is driving it...however if you increase the load on the axle without increasing the torque, the RPM will decline. Get it? That is power being consumed - the torque does not change.Go back to school.
quote: Because weight doesn’t change with speed, the drag force due to weight doesn’t change with speed.
quote: Therefore the power consumed due to weight scales linearly with velocity or is proportional to mass times velocity.
quote: The drag force due to aero drag scales with the square of velocity. Therefore the power consumed due to velocity (aero drag) scales with the cube of speed or is proportional to velocity cubed.
quote: Adding the results of the linear function and the cube function creates a third function in which mass and velocity still feature separately. That third function is NOT proportional to the square of speed. Mass times velocity is NOT a constant and so cannot be factored out along with the other constants when figuring out proportionality. I’m not wrong about this.
quote: That went straight over your head. The Tesla’s weight and tires will result in a rolling resistance of 56lb force. If you think that is insignificant to the point of being practically zero when compared to aero drag then what else can I say. Either you can’t understand or you won’t understand and neither of these makes you look good.
quote: An EV is not like one of your model aircraft and the correct terminology is Motor controller specifically so people like you won’t become confused. I posted this on the 4/16/2014 in this thread so it is what I have been saying all long.
quote: The advantage of full torque from zero is not having to have a clutch (or torque converter).The advantage is not having to have a clutch. It’s a mechanical simplification.
quote: In the case of Tesla the range of the motor is so broad that it also doesn’t need a gearbox and can make do with a single reduction ratio. A further mechanical simplification. The net result of this is lower weight better reliability and reduced cost.
quote: So if torque is not consumed and power is consumed and power is torque x RPM then really it is just RPM that is being consumed?? LOL. You’re funny.
quote: All that and you still haven’t said were torque in an idling engine is being transferred to.
quote: How does it feel Eric being bested by a “dim-witted buffoon”. Nothing in this world is free Eric not even cheap shots.
quote: We're not talking about economics, skippy, the point was that electric power generation is inherently inefficient...and the fact that you totally veered off topic is basically you conceding that I PWNED your pathetic liberal arguments in favor of electric cars.
quote: While an electric motor does a great job of converting electrical energy into mechanical work, when you consider the fact that the the fuel consumed to generate said electricity is far greater than the energy wasted by gasoline and diesel engines as heat, we can clearly see the SCAM that is being perpetuated by the whole "green energy" political agenda.
quote: It all fits into the broader left-wing agenda of deception, the notion that "climate change" is caused by human activity and supported by dim-witted buffoons like yourself, who fail to realize that being educated today is more of a liability than an asset.
quote: I just find efficiency of generation secondary to anything that has real world effects.
quote: So efficiency should really only be considered within a single fuel type unless you apply some sort of compensating factor.
quote: By the way you did bring up energy independence in your side bar. Electric car = 100% US sourced energy, ICE age car = 30% US sourced energy, 70% imported energy. +1 for the EV
quote: Like I said where I live 70% hydroelectric generation. No fuel consumed there just falling water. Most of this generating capacity was built prior to environmentalism becoming fashionable. No green agenda involved. No tax breaks for EV's here either.
quote: Oh WOW, just WOW. So education and the educated are the enemy. I guess that means ignorance is an asset.
quote: Abusive name calling and personal attacks add nothing to the debate and really only serves to depreciate your cause.
quote: People usually resort to this behavior because they have lost the rational argument and are basically trying to create an emotional fist fight where they try to wound with words rather than admitting defeat.
quote: When you start calling me a dim-witted buffoon for occupying a position I haven’t well that shot misses the mark by a mile. While I can admire a never say die atitude I do read these outbursts as victory.
quote: You have to exclude the inconvenient fact that electricity generation is inherently inefficient
quote: Efficiency is not an end in itself but a means to another end. Its good EV’s are efficient because their batteries can be smaller and because they use electricity that someone has to pay for but that is where it stops at the plug.
quote: Thank you for playing.