Are Electric Cars the biggest con on the planet?

[bigothunter]

otolith said:

bigothunter said:

The need for low mass (and associated high efficiency) is a fundamental engineering principle.

The effect of mass on in-use energy efficiency has been very much diminished by the use of regenerative hybrid and EV powertrains. It's still there, but much less important when you're throwing away 30% of your kinetic energy under braking rather than 100% of it. Low frontal area and Cd more relevant.

Motor industry has given limited attention to CdA reduction for too long. Forty years ago, the aerodynamic new Sierra was applauded but relatively little progress has been made since.

Mild hybrid ICEVs recover some kinetic energy through regen. Hybrids with larger batteries (eg PHEVs) should have comparable kinetic energy recovery to BEVs.

My engineering principle remark was broad. Equally applies to structures - even bridges benefit from low mass / high efficiency.

[bigothunter]

Pixelpeep Electric said:

This will be my last response to you regarding this point.

[SpeckledJim]

bigothunter said:

SpeckledJim said:

The obsession with weight is a 'car guy' thing, and 95% of those 'car guys' go on to lease an Audi A6 anyway.

The need for low mass (and associated high efficiency) is a fundamental engineering principle.

Granted, but it's one that gets largely ignored because we would all rather have 22-way heated and ventilated seats instead of a car that was 30kg lighter.

A good automotive engineer is a person who can build for 100€ what a mediocre car engineer would need all of 113€ to accomplish.

Faced with light or cheap, very few car companies go for light. Because they know that price is more important.

This isn't NASA. We want a big, safe car, stuffed with features and a massive grille with shiny trim. If it weighs 2 tons then it weighs 2 tons. Tell me I can have 3% better fuel economy if I do without my massive grille and shiny trim and I'll thank you to not tell me again because just no.

[OutInTheShed]

bigothunter said:

R Mutt said:

At least this is cheap when those who can't afford a Taycan are eventually forced to drive something from a dystopian sci-fi film

Renault Twizy, Citroen Ami and Wuling Hongguang Mini EV are showing the way forward in a divided BEV market.

Manufactured in low labour cost territories (principally Asia but also Spain, Turkey and Eastern Europe), these cheap products make sound marketing and business sense. A route to generating interest in cars from the disillusioned younger generation.

How many people would rather drive one of those than get the bus?

[otolith]

bigothunter said:

otolith said:

bigothunter said:

The need for low mass (and associated high efficiency) is a fundamental engineering principle.

The effect of mass on in-use energy efficiency has been very much diminished by the use of regenerative hybrid and EV powertrains. It's still there, but much less important when you're throwing away 30% of your kinetic energy under braking rather than 100% of it. Low frontal area and Cd more relevant.

Motor industry has given limited attention to CdA reduction for too long. Forty years ago, the aerodynamic new Sierra was applauded but relatively little progress has been made since.

Mild hybrid ICEVs recover some kinetic energy through regen. Hybrids with larger batteries (eg PHEVs) should have comparable kinetic energy recovery to BEVs.

My engineering principle remark was broad. Equally applies to structures - even bridges benefit from low mass / high efficiency.

Yes, agreed. I specifically referred to in-use, because more mass means more stuff which usually means higher cost and more materials and energy required to build it - even setting aside the component which is principally adding the mass, everything else has to be beefed up to match. A lighter battery should mean a lighter car to carry and propel it.

[bigothunter]

SpeckledJim said:

Granted, but it's one that gets largely ignored because we would all rather have 22-way heated and ventilated seats instead of a car that was 30kg lighter.

A good automotive engineer is a person who can build for 100€ what a mediocre car engineer would need all of 113€ to accomplish.

Faced with light or cheap, very few car companies go for light. Because they know that price is more important.

This isn't NASA. We want a big, safe car, stuffed with features and a massive grille with shiny trim. If it weighs 2 tons then it weighs 2 tons. Tell me I can have 3% better fuel economy if I do without my massive grille and shiny trim and I'll thank you to not tell me again because just no.

Took forty-six years to add 552 kg and 74% weight increase to a basic car. That's some achievement

1974 Volkswagen Golf 1100 kerb 750 kg

2020 Volkswagen Golf 1.0 eTSI kerb 1302 kg

Edited by bigothunter on Monday 13th March 15:38

[bigothunter]

OutInTheShed said:

bigothunter said:

R Mutt said:

At least this is cheap when those who can't afford a Taycan are eventually forced to drive something from a dystopian sci-fi film

Renault Twizy, Citroen Ami and Wuling Hongguang Mini EV are showing the way forward in a divided BEV market.

Manufactured in low labour cost territories (principally Asia but also Spain, Turkey and Eastern Europe), these cheap products make sound marketing and business sense. A route to generating interest in cars from the disillusioned younger generation.

How many people would rather drive one of those than get the bus?

A large majority. Buses are an awful mode of transport except in city and town centres.

[DonkeyApple]

R Mutt said:

At least this is cheap when those who can't afford a Taycan are eventually forced to drive something from a dystopian sci-fi film

I doubt that t. It's well known that those who can't afford a brand new Porsche Taycan in 2035 will simply be put against a wall and executed for being losers. Most people have just 12 years to live before it's all aboard the death camp choo choo.

[MisterBigglesworth]

OutInTheShed said:

How many people would rather drive one of those than get the bus?

Imagine it will be fun when a 2.5 ton SUV slams into you.

[dvs_dave]

MisterBigglesworth said:

Imagine it will be fun when a 2.5 ton SUV slams into you.

I’d imagine not a whole lot different to the same happening in a SMART car, and no one particularly complains about them. Circa 500 kg vs 750 kg.

[Diderot]

dvs_dave said:

MisterBigglesworth said:

Imagine it will be fun when a 2.5 ton SUV slams into you.

I’d imagine not a whole lot different to the same happening in a SMART car, and no one particularly complains about them. Circa 500 kg vs 750 kg.

It looks like you don't need anyone to slam into you with one of these:

https://twitter.com/AutoPap/status/163488743210474...

[Challo]

OutInTheShed said:

bigothunter said:

R Mutt said:

At least this is cheap when those who can't afford a Taycan are eventually forced to drive something from a dystopian sci-fi film

Renault Twizy, Citroen Ami and Wuling Hongguang Mini EV are showing the way forward in a divided BEV market.

Manufactured in low labour cost territories (principally Asia but also Spain, Turkey and Eastern Europe), these cheap products make sound marketing and business sense. A route to generating interest in cars from the disillusioned younger generation.

How many people would rather drive one of those than get the bus?

Went to Rome last year and these seemed very popular. Perfect cars for European cities.

[GT9]

Evanivitch said:

AstonZagato said:

Heavier battery means bigger brakes, heavier chassis, more cooling, less performance, less engaging to drive, and less range. Vicious circle. If the energy density were to quadruple, you'd probably settle on, say, twice the range and half the weight rather than four times the range.

Ultimately there is a sweet spot in the range/weight equation. It might not suit everyone - so there will be LR cars and performance versions, I guess

Edited by AstonZagato on Sunday 12th March 18:29

When we say heavier do we also mean more powerful and more energy storage?

A larger battery can easily absorb and deploy greater amounts of power without heating. That reduces your need for friction brakes as greater regeneration available and reduces the thermal requirements on the cooling system as the system is far less stressed.

More power is greater acceleration, and if packaged and used with modern dynamic torque control systems can make the vehicle increasingly agile compared when you have 3 or 4 independent motors on a vehicle.

As you've said, it's important to understand that the power available from the battery is related to its size.

Essentially, for two batteries that have the same voltage rating, the larger one will have a lower internal resistance, which affects the voltage drop (and heating) across the battery.

More current can be drawn from the larger battery, and because they both have the same voltage, this means more powaaa!

The larger battery adds more overall performance because the proportional power increase is far higher than the proportional kerb mass increase.

For extreme performance, a higher battery voltage is very desirable.

[Evanivitch]

bigothunter said:

Motor industry has given limited attention to CdA reduction for too long. Forty years ago, the aerodynamic new Sierra was applauded but relatively little progress has been made since.

There's been huge advances in Cd, or is your point more about the increase in vehicle size?

[ruggedscotty]

GT9 said:

As you've said, it's important to understand that the power available from the battery is related to its size.

Essentially, for two batteries that have the same voltage rating, the larger one will have a lower internal resistance, which affects the voltage drop (and heating) across the battery.

More current can be drawn from the larger battery, and because they both have the same voltage, this means more powaaa!

The larger battery adds more overall performance because the proportional power increase is far higher than the proportional kerb mass increase.

For extreme performance, a higher battery voltage is very desirable.

What type of battery are you talking about. sometimes the smaller ones pack alot more punch. Being in and around batteries there aere many variables to take into consideration. And its not just the battery that matters but the load too. needs to be matched.

The higher voltage will only take it so far and then the power will drop. its not cut and dried....

https://nrsyed.com/2018/01/21/how-to-read-a-dc-mot...

[SWoll]

bigothunter said:

Took forty-six years to add 552 kg and 74% weight increase to a basic car. That's some achievement

1974 Volkswagen Golf 1100 kerb 750 kg

2020 Volkswagen Golf 1.0 eTSI kerb 1302 kg

Edited by bigothunter on Monday 13th March 15:38

They aren't comparable though as the current golf is considerably bigger and is no longer a basic car.

The Up is the nearest VW product in size and spec to the MK1 Golf and weighs 930KG.

[bigothunter]

Evanivitch said:

There's been huge advances in Cd, or is your point more about the increase in vehicle size?

Yes aerodynamic drag.

Quick search revealed Saab Sonett III (Model 97) as the production car with lowest CdA, even though its Cd is a moderate 0.31. Sonett III was manufactured from 1970 to 1974. Large cars conflict with low aero drag.

[dvs_dave]

Evanivitch said:

bigothunter said:

Motor industry has given limited attention to CdA reduction for too long. Forty years ago, the aerodynamic new Sierra was applauded but relatively little progress has been made since.

There's been huge advances in Cd, or is your point more about the increase in vehicle size?

Indeed. What’s gotten worse is the frontal area of modern vehicles, because they’re just so much bigger. That of course undoes much of the gains achieved from the much improved Cd’s of modern vehicles. It’s no coincidence that the longest range/most efficient vehicles are a saloon/fastback car format.

[bigothunter]

SWoll said:

bigothunter said:

Took forty-six years to add 552 kg and 74% weight increase to a basic car. That's some achievement

1974 Volkswagen Golf 1100 kerb 750 kg

2020 Volkswagen Golf 1.0 eTSI kerb 1302 kg

They aren't comparable though as the current golf is considerably bigger and is no longer a basic car.

Which reinforces my point. Even the base model Golf is laden with trinkets and become bloated over the years.

SWoll said:

The Up is the nearest VW product in size and spec to the MK1 Golf and weighs 930KG.

VW Up is a city car competing with Toyota iQ. Certainly not comparable to any Golf.

VW Polo might be a worthy comparator to original Golf. Base model Polo weighs in at 1106 kg (additional 356 kg and 47%). Almost a lightweight


Considering their heavy batteries, getting EVs down to sensible weights (and cost) is a real challenge.

[SWoll]

bigothunter said:

VW Up is a city car competing with Toyota iQ. Certainly not comparable to any Golf.

VW Polo might be a worthy comparator to original Golf. Base model Polo weighs in at 1106 kg (additional 356 kg and 47%). Almost a lightweight


Considering their heavy batteries, getting EVs down to sensible weights (and cost) is a real challenge.

The Up is comparable to the MK1 Golf in size and performance. Read any review of the UP GTi and comparisons will be made with the MK1 Golf GTi.

The current Polo is considerably bigger and similar in size to a MK3 Golf which weighed 1000KG+. The BMW i3, which is again a similar size, with a 42kWh battery weighs 1300KG.