The powers of EV's
Discussion
robinessex said:
aizvara said:
robinessex said:
Good question. From the clips on youtube, seems as if quite a few aren't. But Lambos, and others, do project speed and power, so I assume potential buyers are well aware of what they've got. However, if Sharon jumps into hubby's 1000bhp, 1g acceleration EV, to pop down to Tesco for some milk, I'm wonder what an inadvertent prod of the right pedal would result in?
I don't know about Teslas but my partially electric driven car has various modes including those for normal, round town driving, off road, and "sport". Those massively affect throttle response, steering feel,driven wheels, and similar. That's with a third of the power of the Tesla you mention but I imagine it isn't beyond the wit of their engineers to build a similar system for drivability in a range of scenarios. 
Maracus said:
robinessex said:
aizvara said:
robinessex said:
Good question. From the clips on youtube, seems as if quite a few aren't. But Lambos, and others, do project speed and power, so I assume potential buyers are well aware of what they've got. However, if Sharon jumps into hubby's 1000bhp, 1g acceleration EV, to pop down to Tesco for some milk, I'm wonder what an inadvertent prod of the right pedal would result in?
I don't know about Teslas but my partially electric driven car has various modes including those for normal, round town driving, off road, and "sport". Those massively affect throttle response, steering feel,driven wheels, and similar. That's with a third of the power of the Tesla you mention but I imagine it isn't beyond the wit of their engineers to build a similar system for drivability in a range of scenarios. Maracus said:
Personally, we charge 99% at home, and never get near any range anxiety. I wouldn't want the car to default to Chill or Green Plus unless I was approaching a single figure % and wasn't confident I could get a charge, which hasn't happened in 3 years.
Makes negligible difference anyway IME. Turning down heating/air con has far more affect assuming you're being sensible with the go pedal and I would rather have the additional performance immediately available should it be needed.Our etron has numerous modes for the drivetrain and tried them all with little affect on efficiency or range, same with our Model 3 P in chill mode.
robinessex said:
Surely a 4x4 with 250hp would be sufficient?
Our etron has a power meter that show you exactly how much you are using at any point + regen. I doubt we go above 50% (200hp) the majority of the time. It is handy having the full 400hp + Boost in certain situations though. 
Edited by SWoll on Thursday 16th March 10:24
SWoll said:
Maracus said:
Personally, we charge 99% at home, and never get near any range anxiety. I wouldn't want the car to default to Chill or Green Plus unless I was approaching a single figure % and wasn't confident I could get a charge, which hasn't happened in 3 years.
Makes negligible difference anyway IME. Turning down heating/air con has far more affect assuming you're being sensible with the go pedal and I would rather have the additional performance immediately available should it be needed.Our etron has numerous modes for the drivetrain and tried them all with little affect on efficiency or range, same with our Model 3 P in chill mode.
robinessex said:
Surely a 4x4 with 250hp would be sufficient?
Our etron has a power meter that show you exactly how much you are using at any point + regen. I doubt we go above 50% (200hp) the majority of the time. It is handy having the full 400hp + Boost in certain situations though. Edited by SWoll on Thursday 16th March 10:24
robinessex said:
Surely a 4x4 with 250hp would be sufficient?
So why do you have a supercharged 400bhp [whatever] in the garage?You seem to be suggesting that it's OK for richer blokes to drive powerful cars with no training, but anyone else - not so much, particularly if they're a woman.
Maracus said:
To be honest, I've never used Chill mode so can't comment
I tried it in the first couple of days to see what difference it might make in normal daily driving. Totally ruined the experience and did bugger all for efficiency when driving sensibly anyway therefore never touched it again for the next 2 years and 20k miles. robinessex said:
aizvara said:
robinessex said:
Good question. From the clips on youtube, seems as if quite a few aren't. But Lambos, and others, do project speed and power, so I assume potential buyers are well aware of what they've got. However, if Sharon jumps into hubby's 1000bhp, 1g acceleration EV, to pop down to Tesco for some milk, I'm wonder what an inadvertent prod of the right pedal would result in?
I don't know about Teslas but my partially electric driven car has various modes including those for normal, round town driving, off road, and "sport". Those massively affect throttle response, steering feel,driven wheels, and similar. That's with a third of the power of the Tesla you mention but I imagine it isn't beyond the wit of their engineers to build a similar system for drivability in a range of scenarios. Killowatts times hours, not divided by.
The power used to accelerate an EV is indeed high, it does not however last for very long, so it's not a high energy event compared to the energy needed to push the car through air or roll the tyres over the ground for a reasonable distance.
The second major thing you've overlooked is that all power used to accelerate the car is carried as kinetic energy until you apply the brakes, or use it for coasting.
In an ICE, that energy is lost to friction and heat in the brakes if braking is used to slow the car.
IN an EV, up to 75% of it is recoverable back to the battery by regenerative braking.
Coasting is 100% effective use in both vehicle types.
EVs use a different design rule book, so your 'concern' is misplaced.
As for the actual deployment of the power, most EVs only have a single speed gearbox.
Typically, you could call it the equivalent of 3rd gear.
What this means is that the motor cannot deliver full power from standstill, it can only deliver full torque.
You never get access to full power at low road speeds, it's simply not possible without breaking traction and significantly spinning up the wheels.
Conversely a multi-ratio gearbox will give you access to the engine's full power rating at a far lower road speed (in first and second gear).
This causes torque spikes at the driven wheels that can lead to loss of traction and control, spike that aren non-existent in the EV, which just applies the same torque at the driven wheels at ALL speeds, until the motor goes into its constant power mode.
This mode is usually above say 60 mph.
The lack of torque spikes that gears and clutches create and the torque oscillations that a reciprocating intermittently firing engine creates means that the driven tyres have a far easier life in an EV, which helps to mitigate for the marginal extra mass that they are carrying.
The actual torque spike seen in first gear in an ICE at the wheels is far higher in magnitude than what an EV can muster, DESPITE the headline torque rating of the EV being higher than the ICE.
Quoting and comparing the torque figures at the engine and motor are fairly useless if you don't take the effect of gearing into account.
Did I mention that the design rule book is different...
Full beans electric acceleration, despite being faster, is inherently less 'dangerous', because the motor is applying the exact amount of torque to the road that is required to accelerate the car throughout the acceleration event.
An ICE attempts to mimic this with the use of a multi-ratio gearbox, but ends up delivering a very rough approximation where the torque at the driven wheels is either too little or too much for a lot of the acceleration event.
The 'too much' bits are where it can go pear-shaped, hence the myriad of hedge-finding episode you can witness on youtube when a powerful (typically rear drive) ICE is overcooked.
smn159 said:
robinessex said:
Surely a 4x4 with 250hp would be sufficient?
So why do you have a supercharged 400bhp [whatever] in the garage?You seem to be suggesting that it's OK for richer blokes to drive powerful cars with no training, but anyone else - not so much, particularly if they're a woman.
GT9 said:
What this means is that the motor cannot deliver full power from standstill, it can only deliver full torque.
Valid points, as you say, there is a difference. Just to be pedantic, Mr Newton worked out many years ago you require a FORCE to move (accelerate) a mass. That force in a vehicle is TORQUE. You can mimic it in an ICE car, with a torque conveyor, by full revs with the brakes on, and then releasing them.robinessex said:
Maracus said:
robinessex said:
aizvara said:
robinessex said:
Good question. From the clips on youtube, seems as if quite a few aren't. But Lambos, and others, do project speed and power, so I assume potential buyers are well aware of what they've got. However, if Sharon jumps into hubby's 1000bhp, 1g acceleration EV, to pop down to Tesco for some milk, I'm wonder what an inadvertent prod of the right pedal would result in?
I don't know about Teslas but my partially electric driven car has various modes including those for normal, round town driving, off road, and "sport". Those massively affect throttle response, steering feel,driven wheels, and similar. That's with a third of the power of the Tesla you mention but I imagine it isn't beyond the wit of their engineers to build a similar system for drivability in a range of scenarios. . My Ovlov BEV has 408bhp. Each and every horse is essential of course. 
One thing that took me a little by surprise on the test drive was not so much the BHP - I’ve had more powerful cars before - rather the instant torque when overtaking.
Diderot said:
robinessex said:
Maracus said:
robinessex said:
aizvara said:
robinessex said:
Good question. From the clips on youtube, seems as if quite a few aren't. But Lambos, and others, do project speed and power, so I assume potential buyers are well aware of what they've got. However, if Sharon jumps into hubby's 1000bhp, 1g acceleration EV, to pop down to Tesco for some milk, I'm wonder what an inadvertent prod of the right pedal would result in?
I don't know about Teslas but my partially electric driven car has various modes including those for normal, round town driving, off road, and "sport". Those massively affect throttle response, steering feel,driven wheels, and similar. That's with a third of the power of the Tesla you mention but I imagine it isn't beyond the wit of their engineers to build a similar system for drivability in a range of scenarios. . My Ovlov BEV has 408bhp. Each and every horse is essential of course. One thing that took me a little by surprise on the test drive was not so much the BHP - I’ve had more powerful cars before - rather the instant torque when overtaking.
robinessex said:
GT9 said:
What this means is that the motor cannot deliver full power from standstill, it can only deliver full torque.
Valid points, as you say, there is a difference. Just to be pedantic, Mr Newton worked out many years ago you require a FORCE to move (accelerate) a mass. That force in a vehicle is TORQUE. You can mimic it in an ICE car, with a torque conveyor, by full revs with the brakes on, and then releasing them.The Koenigsegg Regera is a fantastic example of how to make an ICE into the perfect acceleration device.
That car uses a bespoke torque converter (with high stall speed) and electric motors for torque fill.
I'd say that car was a milestone event where it became beyond question that the game was up in the ICE vs EV acceleration stakes.
robinessex said:
What others have and enjoy doesn't interest me?
robinessex said:
I have diddly squat interest in EVs, but the power outputs 'worry' me.
Which is it, you don't care or you do?Your old fashioned 400bhp snotter is far more of a liability to others on the road than an modern EV
GT9 said:
It is telling that one of the fastest accelerating ICE road cars ever seen has a kerb mass of around 1500 kg AND doesn't have a multi-ratio gearbox.
The Koenigsegg Regera is a fantastic example of how to make an ICE into the perfect acceleration device.
That car uses a bespoke torque converter (with high stall speed) and electric motors for torque fill.
I'd say that car was a milestone event where it became beyond question that the game was up in the ICE vs EV acceleration stakes.
£2 million and still slower over the 1/4 mile than a £125k 5 door Tesla saloon.The Koenigsegg Regera is a fantastic example of how to make an ICE into the perfect acceleration device.
That car uses a bespoke torque converter (with high stall speed) and electric motors for torque fill.
I'd say that car was a milestone event where it became beyond question that the game was up in the ICE vs EV acceleration stakes.
The similarly price Rimac Nevera EV supecar is considerably quicker again.
100% agree, the game is up.
JD said:
robinessex said:
What others have and enjoy doesn't interest me?
robinessex said:
I have diddly squat interest in EVs, but the power outputs 'worry' me.
Which is it, you don't care or you do?Your old fashioned 400bhp snotter is far more of a liability to others on the road than an modern EV
robinessex said:
All the 'liability' I see on the roads seems to be the fault of the driver, independent of the type of vehicle they drive.
Yes exactly, as you have already alluded to your own inability to control your own vehicle.robinessex said:
he can be a bit naughty if you get a bit too enthusiastic. Don't ask me how I know.
You are just the type of holier than thou, s
tbox owning driving god I 'worry' about on the roads.robinessex said:
You've totally missed the point. I presume that most who buy an, acknowledged, high-performance sports car know what it's capable of and how to respect it. No problem with that. But EVs seem to be more of a transport device to take me where I want to go, and many I suspect who get to drive one has no idea of the power output, and what can go wrong.
EV owners are not morons. We know they are faster than most ICE - one reason why some people buy them.What does sometimes catch new owners out is the immediacy of the throttle response. More so than the power, which is just as easy to control as it is in any ICE.
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