Random Thoughts... [Automotive Edition]

Matt2000

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Yeah, which is silly, the established brands to me are good at what they do, why couldn't they just build a normal interior with the usual switches and stuff but have a different drive train underneath?
Spaceship! Must look like spaceship!
 

jack_christie

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Interesting ute/pickup group test:
 

DanRoM

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I saw a 508 SW in black yesterday and it looked absolutely gorgeous.
And this version, wow. Too bad almost nobody will buy it because it's a Peugeot. :(
 

93Flareside

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I saw a 508 SW in black yesterday and it looked absolutely gorgeous.
And this version, wow. Too bad almost nobody will buy it because it's a Peugeot. :(

@loose_unit should. Hopefully we can change his mind from that Alfa crossover he's looking at. :p
 

jack_christie

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Not surprising that a new Peugeot didn't get its own thread but this is finally something French that I actually like.

It did
 

gaasc

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@narf ,

Quite some time ago, you did some calculations which gave some more accuracy as to effects of A/C use on EV range. I was trying to look for it and couldn't find it, do you recall anything from it, preferably where it is so as to save loads of typing?

I wanted to see if it would be as bad as making my compact cars do 14 MPG and my large ones doing Single digits on low-speed rush hour situations with hills, but I don't have the required data.
 

narf

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@narf ,

Quite some time ago, you did some calculations which gave some more accuracy as to effects of A/C use on EV range. I was trying to look for it and couldn't find it, do you recall anything from it, preferably where it is so as to save loads of typing?

I wanted to see if it would be as bad as making my compact cars do 14 MPG and my large ones doing Single digits on low-speed rush hour situations with hills, but I don't have the required data.
I did? :dunno:

:think:



This?
 

gaasc

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I believe so, yes.

Thank you. I tend to overestimate the impact of A/C on EV's, apparently.
 

GRtak

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I believe so, yes.

Thank you. I tend to overestimate the impact of A/C on EV's, apparently.


Tesla uses heat pumps because they use less power, maybe others do to?
 

jack_christie

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Heat pump option on Skoda Enyaq iV, so I assume must be possible on other cars based on ID3 or 4.

Possibly on Taycan/etron GT

iPace has one too.
 

Perc

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I saw a 508 SW in black yesterday and it looked absolutely gorgeous.
And this version, wow. Too bad almost nobody will buy it because it's a Peugeot. :(

The 508 is one of the best looking cars in a very long time IMO, SW or not. I would love to have one.

Too bad I can’t see the gauges because the steering wheel is in the way. They say you’re supposed to have the wheel lower down than in most cars but that doesn’t work for me because I have legs. And knees. It’s also way too low for my liking.
 

gaasc

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Tesla uses heat pumps because they use less power, maybe others do to?
That's reassuring...what's a heat pump? :p
 

eizbaer

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That's reassuring...what's a heat pump? :p
An A/C is technically a type of heat pump. technically, so are most fridges.

commonly referred to, a heat pump is just the same principle as A/C only run "in reverse" so to speak to heat up the cabin more efficiently than a resistive heater. the name is actually quite good - as dan said - it literally pumps heat (from a low temperatur to a high temperature usually). That's why the "efficiency" is usually higher than 100%, because it takes the heat and moves it, rather than use the energy put in to convert that to heat.
 

gaasc

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An A/C is technically a type of heat pump. technically, so are most fridges.

commonly referred to, a heat pump is just the same principle as A/C only run "in reverse" so to speak to heat up the cabin more efficiently than a resistive heater. the name is actually quite good - as dan said - it literally pumps heat (from a low temperatur to a high temperature usually). That's why the "efficiency" is usually higher than 100%, because it takes the heat and moves it, rather than use the energy put in to convert that to heat.
So a Tesla using a heat pump means it consumes much less energy when heating up a cabin than resistors and, pertinently to my case, will consume an amount of electricity similar to a normal A/C (defined by narf as about 1kw or so) when cooling it, yes?
 

eizbaer

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So a Tesla using a heat pump means it consumes much less energy when heating up a cabin than resistors and, pertinently to my case, will consume an amount of electricity similar to a normal A/C (defined by narf as about 1kw or so) when cooling it, yes?

My old tesla still has the resistive heater, which will pull up to 7 kW (I think?) of electrical power :(

Usually, aside from crazy outside temperatures, you can think of current heat pumps as working with a coefficient of performance (COP, because "efficiency" > 100% sounds wrong) of about 3-ish, meaning for those 7 kW of heat inside, it'll consume about 2.3 kW electrical power [edit: to clarify, this is only for a spike, like with the A/C - so I'd expect the heat pump to consume on an average cold day way less than 1 kW average over a longer drive, i think there's a teslabjörn video about this somewhere, if you're interested]. When it gets too cold (like -10C or below I'd say) this COP usually plummets (depending on system design), hence there is a resistive heater in front of the heat pump sometimes.

The A/C should operate as narf described, so high electrical draw when first cooling down the car, then settle down somewhere at maybe 1 kW average over a longer drive.

In addition to the heatpump however, the new tesla design has the crazy OCTOVALVE stuff - basically they have a large heat exchanger in a central position where EVERYTHING that's warm or gets cooled or anything can be made to exchange heat with each other. So in addition to having a more efficient heater, they actually harvest heat (or dump heat when they need to get rid of it I guess) from all available components (i.e. motors, battery, whatever). This further improves things, but I have no idea and no way of telling by how much :dunno:
 

GRtak

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