Tesla Unveils Radical Cybertruck.

[Dayaks]

Maybe uphill, on summer tires, spinning without moving.

And plowing the road.

 

[sfsuphysics]

NO GAS EVER...AND NO ELECTRICITY EVER...with the $2k solar panel upgrade option...
https://www.motor1.com/news/384123/solar-powered-cybertruck-added-range/

I'm going to hold back on the accolades of these claims.

The claim is 15 miles per day of charging, looking at the specs that would require about 6.4kWh of solar production, and even in sunny California with it's juicy 5.4 peak hours of sunlight assuming you park just so right so the orientation maximizes production and the angle is perfect (it's not), you'll need about 1.2 kW worth of solar panels, which if you used today's best available panels (which they won't be because they need to be thinner and protected more), you're looking at about 66 square feet for panels, which doesn't look quite like that will fit on the space provided.

 

[Verge]

Per hour, at -36C.

You said, you could lose up to 90% of your range.

In reality it's closer to 10%-20%, even in conditions more extreme than Winter in the coldest of the Lower 48 States.

or 40... derp

https://www.marketwatch.com/story/cold-weather-saps-electric-car-batteries-2019-02-07

 

[Vega]

Pretty funny when you put the numbers into context:

https://www.fueleconomy.gov/feg/coldweather.shtml

Internal combustion engine cars can lose considerable range too in cold weather, especially on short trips.

 

[Gideon]

Pretty funny when you put the numbers into context:

https://www.fueleconomy.gov/feg/coldweather.shtml

Internal combustion engine cars can lose considerable range too in cold weather, especially on short trips.

On the flip side the cold air helps to increase the power the engine produces as cold air is far more dense then warm. Also some of those losses will be negated once the fluids are warm, however there is no way to mitigate the losses on a electric vehicle so far. Electric cars are getting closer tho to being more viable.

 

[Gideon]

Too bad all that cold air is working against you as you're speeding down the interstate😁

True enough but it hurts the electric car too

 

[Snowdog]

On the flip side the cold air helps to increase the power the engine produces as cold air is far more dense then warm.

But, that doesn't improve efficiency, you get more power, in part, because colder air, increases the fuel injected, to keep the fuel-air at stoichiometric ratio.

there is no way to mitigate the losses on a electric vehicle so far

EV motors don't actually lose much efficiency in the cold, because they have very little friction to start with, and it doesn't increase that much in the cold.

Loss of EV range will mainly come from:

1) Cabin heating. This can be mitigated significantly by using seat heaters and steering wheel heaters instead of cabin heating, and using heat pumps for cabin heating(when required), instead of resistance heating elements.
2) Less chemical activity in cold battery - no efficiency is actually lost here - you are just locked out of some capacity, because the chemistry is less active. When the battery warms you get it back. If you actually need the extra range, this can be mitigated by pre-warming the battery in the morning, after a cold night.
3) Denser air at highway speeds - Equal effects regardless of propulsion system, though EVs tend to have superior aerodynamics, so to the impact would waste less energy than vehicles with poorer aero.

 

[Gideon]

But, that doesn't improve efficiency, you get more power, in part, because colder air, increases the fuel injected, to keep the fuel-air at stoichiometric ratio.



EV motors don't actually lose much efficiency in the cold, because they have very little friction to start with, and it doesn't increase that much in the cold.

Loss of EV range will mainly come from:

1) Cabin heating. This can be mitigated significantly by using seat heaters and steering wheel heaters instead of cabin heating, and using heat pumps for cabin heating(when required), instead of resistance heating elements.
2) Less chemical activity in cold battery - no efficiency is actually lost here - you are just locked out of some capacity, because the chemistry is less active. When the battery warms you get it back. If you actually need the extra range, this can be mitigated by pre-warming the battery in the morning, after a cold night.
3) Denser air at highway speeds - Equal effects regardless of propulsion system, though EVs tend to have superior aerodynamics, so to the impact would waste less energy than vehicles with poorer aero.

More power from the engine means less throttle needed to maintain cruising speed and a small boost in fuel mileage. Watched it several times in dyno test rooms and it always works that way.

The batteries have to be heated in a cold environments or they loose massive amounts of capacity and thus becomes a bit of load on them as well and of course in cold weather cabin heating is also a large load. The aero difference is minor and mostly only become a large factor at speeds much higher then most drive unless your driving a brick.

Here is a link that shows the cost of aero of several cars, you will notice at 70mph there is hardly any difference.
https://www.tesla.com/sites/default/files/blog_attachments/the-slipperiest-car-on-the-road.pdf

 

[Snowdog]

Here is a link that shows the cost of aero of several cars, you will notice at 70mph there is hardly any difference.
https://www.tesla.com/sites/default/files/blog_attachments/the-slipperiest-car-on-the-road.pdf

You consider requiring 28% more power to overcome air resistance at 70 mph, to be hardly any difference?

Note also that is this between cars that were all tweaked/designed for good aerodynamics. Not your average sedan.

 

[Gideon]

You consider requiring 28% more power to overcome air resistance at 70 mph, to be hardly any difference?

Yeah because a gas engine at cruising speed is producing around 100 hp, however it helps the most on a electric because any less HP needed equals less battery drain. Gas engines produce more power then needed to cruise, so 18 HP or 14 HP means nothing to the gas engine but a nice gain for the electric car.

 

[Snowdog]

Yeah because a gas engine at cruising speed is producing around 100 hp

You clearly need to do more research, and go back to school on basic physics.

 

[Gideon]

You clearly need to do more research, and go back to school on basic physics.

I worked in dyno cells and engines for years, you can stick to subjects you actually know. Aero only becomes a serious factor at high speeds and thus why sport cars go through so much testing for it, legal freeway speeds not so much.

 

[Tsumi]

You clearly need to do more research, and go back to school on basic physics.

He's not wrong. My 2016 Camry Hybrid produces 200 HP and is capable of well over 120 mph.

 

[Snowdog]

He's not wrong. My 2016 Camry Hybrid produces 200 HP and is capable of well over 120 mph.

He is wrong, because he said it produces it while cruising. At highway cruising speed we are discussing (70 MPH), your Camry is almost certainly producing less than 30 HP. The whole point of fuel economy is produce the least HP possible, and one of the biggest savings you get at highway speeds is reducing aerodynamic drag.

 

[Gideon]

He is wrong, because he said it produces it while cruising. At highway cruising speed we are discussing (70 MPH), your Camry is almost certainly producing less than 30 HP. The whole point of fuel economy is produce the least HP possible, and one of the biggest savings you get at highway speeds is reducing aerodynamic drag.

Umm no at cruising your keeping the rpm down as much as you can and is often achieved with a aggressive overdrive. Most cars run at 2000 rpm or above at 70 mph which produces far more power then 30 HP even on a 4 cylinder closer to around 50 HP, this is why they start to regenerate electric power at freeway speeds as the engine has power to spare. Biggest gain in a electric car is not getting the friction losses present in a full drive train and hybrids loose that advantage. Engine rpm is far more critical to fuel economy and thus why you see 9 speed transmissions these days.

 

[Snowdog]

Aero only becomes a serious factor at high speeds and thus why sport cars go through so much testing for it, legal freeway speeds not so much.

It's serious factor at out discussed legal 70MPH freeway speeds. In fact it's clearly the dominant load at such speeds.

Excluding losses within the engine itself, the consumers of power are from overcoming the following:

Driveline Losses(Transmission and differential gears),
Parasitic (Accessories)
Rolling Resistance
Air Resistance

After 40 MPH, overcoming Air Resistance is already the largest consumer of power. At 70 MPH overcoming Air Resistance, consumes more power than all the others combined.

Here is a simple fuel economy modelling tool, for those interested in seeing the impacts of rolling resistance vs air resistance at various speeds:
https://ecomodder.com/forum/tool-aero-rolling-resistance.php

Finally, you can't produce power in excess of that needed to overcome loads at a specific speed, or your would go faster than that speed. A typical sedan needs less than 30 HP to go 70MPH, if you were producing 100HP would be going MUCH faster than 70 MPH. That one is just a basic physics fail.

 

[Gideon]

Finally, you can't produce power in excess of that needed to overcome loads at a specific speed, or your would go faster than that speed. A typical sedan needs less than 30 HP to go 70MPH, if you were producing 100HP would be going MUCH faster than 70 MPH. That one is just a basic physics fail.

Your confusing reserve capacity vs actual power. You have far more capacity at the same rpm depending on throttle angle. I should have been more clear on that. This is also why all effort on gas engines has been focused on lowering engine rpm and keeping performance up and thus variable valve timing, electronic throttle and other things to increase the efficiency.

 

[Snowdog]

Your confusing reserve capacity vs actual power. You have far more capacity at the same rpm depending on throttle angle. I should have been more clear on that. This is also why all effort on gas engines has been focused on lowering engine rpm and keeping performance up and thus variable valve timing, electronic throttle and other things to increase the efficiency.

You are the one confusing things seemingly implying that at a specific RPM you MUST produce peak power. You did again above:
"70 mph which produces far more power then 30 HP even on a 4 cylinder closer to around 50 HP "

A 4 cylinder might be capable of producing a peak of 50HP at 2000 RPM, but that doesn't mean it will be doing that all the time. The driver/cruise control, will only open the throttle to produce enough power to overcome loads, which will be under 30 HP at 70 MPH.

What an engine can produce at peak is irrelevant red herring to the discussion of freeway energy economy, which implies you don't know what you are talking about.

Back to where you went off the rails.

28% more aerodynamic resistance is a LARGE factor in fuel economy at freeway speeds, because that represents the majority of the load at those speeds. Red Herrings about gas engine peak power don't change the basic physics of needing significantly more fuel, to overcome those significantly larger loads.

 

[MixManSC]

Y'all keep it civil in here. Personal slights and attacks will not be tolerated....

 

[THRESHIN]

Trying to get this derailed thread back on the tracks, I've always thought it is wonderful how Tesla is making a serious attempt at an EV. I'm not going to say they're the best car out there (they aren't) but think of the technology they've developed when nobody else has.

And as far as creating an EV over gas counterpart, well why not? If the product is good enough at the right price.... eventually.... there's going to be a lot of people lined up to buy them. If they can't get it to work, they'll just go under.

My concerns are sustainability and of course the ever important range. I commute and hour each way to work on the highway and I live in Canada. It gets cold here sometimes. For that reason and the cost it's not for me just yet. I'm hoping that it will be in the future.

As far as sustainability, we're building EVs for two reasons: cheaper fuel and the environment. Well...those lithium batteries aren't exactly clean to make or recycle. Mining is always dirty. And then there's the problem of supply. Only so much materials to go around.

I did like the Toyota approach. Was in the news while back, their CEO was mouthing off about how he wanted to hybridize their entire lineup. At least according to him, one plug in hybrid puts out 30% less pollution on average but the materials to build one EV could build 10 hybrids. Maybe that's a better idea until we get a better battery? Maybe batteries aren't the route in the future after all....

Either way, I like developing more tech. We get better stuff for less.

 

[Gideon]

28% more aerodynamic resistance is a LARGE factor in fuel economy at freeway speeds, because that represents the majority of the load at those speeds. Red Herrings about gas engine peak power don't change the basic physics of needing significantly more fuel, to overcome those significantly larger loads.

It is not and never has been a large factor in design. Aero is always a after thought and after design sculpting for looks. All money is put toward reducing powertrain losses and engine fuel efficiency. Your 28% is only 4 HP of difference is just not enough to ruin the aesthetics of a car and it has long been true. Mythbusters did a test with dimpling the car which improved aero but did very little to increase fuel economy granted they increase the weight as well and that is a very important factor as well. You want to continue this your welcome to PM me but I wont bother responding to you in this thread anymore as it has very little to do with the subject.

 

[Tsumi]

There are some interesting battery tech in the pipeline, the real question is whether they will be commercially viable. IMO the biggest game changers in battery tech will be solid-state (no flammability, lower weight, higher charge rates) and cobalt-less (biggest mining pollution source for batteries in my limited research) designs. Safe high voltage charging for rapid charging will also be needed.

A research article pointed to hybrids losing 62% of their energy to aerodynamics vs other sources, so lowering that by 28% is significant.

 

[Gideon]

There are some interesting battery tech in the pipeline, the real question is whether they will be commercially viable. IMO the biggest game changers in battery tech will be solid-state (no flammability, lower weight, higher charge rates) and cobalt-less (biggest mining pollution source for batteries in my limited research) designs. Safe high voltage charging for rapid charging will also be needed.

A research article pointed to hybrids losing 62% of their energy to aerodynamics vs other sources, so lowering that by 28% is significant.

Battery tech is always evolving and getting better, but the weight is still a big problem for them and obviously charging time is hugely important to a owner. Aero is often pointed to but the weight of the vehicle is super important to mileage be it electric or gas powered. Electric is getting closer to being a good choice but price is still a issue as well.

 

[Snowdog]

Your 28% is only 4 HP of difference is just not enough to ruin the aesthetics of a car and it has long been true.

It's the percentage that matters. 28% reduction in what represents 50% or more of the load will result in a 14%+ gain in fuel economy. Squeezing that much more out of modern gas engines isn't really possible. Nothing really has as big an opportunity to produce these kind of benefits. Though Aero only helps at freeway speed. Stop and go pushes other factors back up.

Aero is often pointed to but the weight of the vehicle is super important to mileage be it electric or gas powered.

Weight is important in stop and go, as you waste power overcoming the greater inertia (and you can't recover it all with regen).

For highway trips, Aero trumps all.

Excellent Aero is actually a big reason why the Prius gets excellent highway MPG, when the hybrid system is doing essentially nothing.

You could rip out the batteries and hybrid components, and connect the Prius engine to a Manual transmission and get about the same MPG, because at highway speed, it's simply the aerodynamics that has the largest impact.

It's why the original Honda Insight went so far as to add rear wheel skirts. This car got 60+ MPG on the highway where the mild hybrid system was essentially off. You could throw away the Hybrid system and it would still get 60+ MPG:


Any serious attempt to improve fuel economy, attacks it from all angles: Weight, Aero, Engine efficiency, parasitic losses.

 

[Tsumi]

Battery tech is always evolving and getting better, but the weight is still a big problem for them and obviously charging time is hugely important to a owner. Aero is often pointed to but the weight of the vehicle is super important to mileage be it electric or gas powered. Electric is getting closer to being a good choice but price is still a issue as well.

Getting rid of cobalt will reduce prices, and solid state will reduce weight. If one can recharge 300 miles in 5-10 min, most people won't care about cars hitting 350+ mile range. Efficiency won't be as big a deal if energy comes from renewable sources and we have a surplus of said energy.

 

[Gideon]

Getting rid of cobalt will reduce prices, and solid state will reduce weight. If one can recharge 300 miles in 5-10 min, most people won't care about cars hitting 350+ mile range. Efficiency won't be as big a deal if energy comes from renewable sources and we have a surplus of said energy.

True enough there, bigger picture is energy cost and sources. Tho I know Hydrogen powered cars are starting to gain traction there as well but cost is still high for Hydrogen but getting closer to the cost of gas. Will be interesting to see what way ends up being the more popular route or which ones the manufactures decide to bring forward to the public.

 

[kju1]

It is not about poor planning. It is more about being cheap/poor. People are stupid and try to get every drop out their tank. You never been through a poor area have you? I see it all time stopping by a gas station in poor area where people are buying gas with what little change in their pocket. Those are the people that run out of gas.

This cant be true because I am constantly told poor people only take public transportation and do not drive. Thus things like high tolls do not impact them. EDIT: Adding a /sarcasm tag...in case you didn't get it.

Its not about being cheap/poor. Its about being stupid. You got part of it right. When I couldn't afford the gas to make it all the way I didn't drive. I either walked or took the bus.

 

[Deleted member 243478]

Battery tech is always evolving and getting better, but the weight is still a big problem for them and obviously charging time is hugely important to a owner. Aero is often pointed to but the weight of the vehicle is super important to mileage be it electric or gas powered. Electric is getting closer to being a good choice but price is still a issue as well.

Weight doesn’t have a huge detriment at cruising speeds, aero is the biggest challenge for EVs as they get worse range in freeways. Once regulations finally get updated to allow things like no side mirrors and more radical designs we can see some real improvements

 

[Gideon]

Weight doesn’t have a huge detriment at cruising speeds, aero is the biggest challenge for EVs as they get worse range in freeways. Once regulations finally get updated to allow things like no side mirrors and more radical designs we can see some real improvements

City driving is the biggest cost of fuel mileage. Also many live in cities where stop and go on the freeway is a reality and yeah it hurts the EV's to be heavy. Also those big tires people like is killing their mileage as well

 

[Tsumi]

City driving is the biggest cost of fuel mileage. Also many live in cities where stop and go on the freeway is a reality and yeah it hurts the EV's to be heavy. Also those big tires people like is killing their mileage as well

It's also where EVs have the biggest advantage. People are impatient and want to stop and go fast, even if it doesn't get them anywhere faster than just coasting to a stop. The more powerful electric motors of full EVs can recapture much more of that momentum than a hybrid, where the weak motors are barely capable of capturing energy during hard braking.

The trend towards big wheels is ridiculous. There's absolutely no reason why a commuter car needs 16" brakes and 18" wheels. It's even more silly when a commuter car has 22" wheels on 14" brakes.

 

[Gideon]

Instant torque of electric motors is nice and it does help but them 22's and a lead foot not so much But yeah a EV in general gets better mileage in city then any gas vehicle ever could. But to much stop and go and you will notice a large reduction in the EV range as well just a bigger hit to gas rigs.

 

[Deleted member 243478]

City driving is the biggest cost of fuel mileage. Also many live in cities where stop and go on the freeway is a reality and yeah it hurts the EV's to be heavy. Also those big tires people like is killing their mileage as well

With combusion engines yes, EVs are the other way around with worse range on freeways due to drag. Tesla claim an 11% increase in range by just ditching the side mirrors.

 

[Tsumi]

I was under the impression ev and hybrids did exceedingly well in stop and go traffic where crawling or idling is paramount.

But....but muh rims bruh?!

View attachment 249801

Much better than gasoline cars. Depending on how its driven, city mileage can exceed highway mileage.

Instant torque of electric motors is nice and it does help but them 22's and a lead foot not so much But yeah a EV in general gets better mileage in city then any gas vehicle ever could. But to much stop and go and you will notice a large reduction in the EV range as well just a bigger hit to gas rigs.

It depends. If you're staying within the regen range during braking, loss of range is almost negligible. I've driven a Tesla and really like the single pedal driving style for maximizing regen. On my Camry hybrid (and other hybrids like the Ford Fusion), you have no idea where the regen maxes out and the braking begins. Also, the lower the speed, the quicker the regen slows down the car.

Well I'm not sure about them side mirrors gone. I love mine in the pickup. Sure they're like two big pillows, but hot dang! that visibility cnt be beat!

A good camera system can provide the same or better visibility with significantly less drag. They're already popping up in European cars, though outdated DOT regulations prevent that in the US.

 

[kju1]

A good camera system can provide the same or better visibility with significantly less drag. They're already popping up in European cars, though outdated DOT regulations prevent that in the US.

A good side mirror will last longer than the car itself and will never fail unless physically hit. I would wonder what the service life of a always on camera is. Plus there's the issue of the camera getting dirty. Half the people I know that own Teslas dont know where the cameras are to clean them (they aren't hard to spot) but they all know where side mirrors are. Oh and in an electrical failure the camera doesn't work but the side mirror would.

I am all for progress usually but I am not sure removing side mirrors is a good thing just yet. Besides they can engineer mirrors that would minimize the drag.

 

[Liver]

A good side mirror will last longer than the car itself and will never fail unless physically hit. I would wonder what the service life of a always on camera is. Plus there's the issue of the camera getting dirty. Half the people I know that own Teslas dont know where the cameras are to clean them (they aren't hard to spot) but they all know where side mirrors are. Oh and in an electrical failure the camera doesn't work but the side mirror would.

I am all for progress usually but I am not sure removing side mirrors is a good thing just yet. Besides they can engineer mirrors that would minimize the drag.

you’ll get more mileage from a good pair of sneakers.

 

[Tsumi]

A good side mirror will last longer than the car itself and will never fail unless physically hit. I would wonder what the service life of a always on camera is. Plus there's the issue of the camera getting dirty. Half the people I know that own Teslas dont know where the cameras are to clean them (they aren't hard to spot) but they all know where side mirrors are. Oh and in an electrical failure the camera doesn't work but the side mirror would.

I am all for progress usually but I am not sure removing side mirrors is a good thing just yet. Besides they can engineer mirrors that would minimize the drag.

Our security cameras were going for 15+ years, 24/7, unlike a car would be. So yes, they can be very robust, it just comes down to the choices the automaker makes on quality.

 

[Gideon]

Our security cameras were going for 15+ years, 24/7, unlike a car would be. So yes, they can be very robust, it just comes down to the choices the automaker makes on quality.

Hate to tell you they usually pick the cheapest components as possible. They tend to keep a eye at 7 years anything beyond that they figure is to costly, they also expect a 15% failure rate before 7 years.

 

[kju1]

Our security cameras were going for 15+ years, 24/7, unlike a car would be. So yes, they can be very robust, it just comes down to the choices the automaker makes on quality.

Those cameras were probably built with "old school cameras" whereas the car cameras are probably more along the lines of the current brand of chip based cameras in terms of quality. And I can say the current chip based cameras do not last that long. My personal experience with security cameras from several manufacturers is 3-5 years. Ive had as little as 1 year from a FossCam.

 

[Snowdog]

Our security cameras were going for 15+ years, 24/7, unlike a car would be. So yes, they can be very robust, it just comes down to the choices the automaker makes on quality.

Yeah, I see no reason for any kind of durability issues here, it's solid state electronics. Just FUD. If you are worried about solid state electronics failing, you need to be driving a car from the 1970's.

Also mirrors get hit a lot. My mothers car is driving around with an unpainted mirror one one side, because it was taken out, and she didn't want to pay extra to have it painted to match.

Ditch the mirrors, and bring on the 360 degree camera views to eliminate blind spots.

 

[odditory]

Plus there's the issue of the camera getting dirty. Half the people I know that own Teslas dont know where the cameras are to clean them (they aren't hard to spot) but they all know where side mirrors are. Oh and in an electrical failure the camera doesn't work but the side mirror would.

I am all for progress usually but I am not sure removing side mirrors is a good thing just yet. Besides they can engineer mirrors that would minimize the drag.

What issue? You don't seem to understand them. They are not exposed to the elements, they're sealed and behind a casing. There's nothing to clean.

A side mirror is also useless in low light and darkness other than for annoying headlights. Cameras can see a whole lot more.

Physical mirrors will also not do anything to help record and document anything, like vandalism to your car, or being rear ended or side-impacted by some idiot who tries to lie and say it wasn't his fault. Extra cameras will.

As for mirrors "never failing" I wish that were the case - the driver-side on my car has turned dark orange and crystallized with weird fractal patterns, and a valet told me "I see a lot of this car with that mirror problem".

Sorry grandpa but our camera sideviews are coming.