Well, that was Ludicrous!

[MikeInWimbledon]

Most of the noise of a modern car is tyre noise anyway especially at high speed (90% plus of motorway noise is from the tyre/road surface interface)...or very low speed when an ICE is just above idle anyway....I cant see EVs as much more dangerous to pedestrians than ICE cars.
However is lots of reports on braking (see Google!) EVs take LONGER to stop than ICE vehicles not shorter........but only by a few feet. How powerful the brakes are on a modern car is irrelevant as all modern cars have the braking power to easily reach the tyre limits..........what determines how fast they stop is the tyre choice (EVs tend to come with tyres designed for high range rather than high grip!!), rear to front weight transference and the mass of the car.....which is why on average EVs take a little longer to stop.... there is just more to stop! If they were identical apart from having a battery motor then they would stop in the same time.

Why do electric cars have longer braking distances?

A reader is thinking of buying an electric car and wonders why they seem to have lengthy stopping distances

www.whatcar.com

I see your point but around the school yard, it's not the technical limits that come into play, it's the "bloody hell, this thing brakes quick" element of what happens when someone hits the brakes in an EV.

Coming off the berries and onto that barely used left hand pedal produces prodigious braking force.

But, as discussed earlier, the Rozzers and statisticians aren't reporting any kind of increased casualty numbers on suburban roads from BEV's and hybrids - as far as I'm aware.

 

[MikeInWimbledon]

and also… surely having more BEVs being used near schools is a good thing, unless people think those walking around there would be better off inhaling the noxious fumes coming out of idling oil burners?

Exactly.

Some might argue that getting obese 11 years olds to walk, scoot, or cycle to school might be a better thing, of course.

Or just moving parents into cheap, very affordable, lighter, smaller Euro6 ICE...

 

[BTB 500]

I suspect cars moving silently under electric power (whether hybrid or EV) are more of an issue in busy car parks ... when reversing out of a space, for example. On the plus side though low speed collisions are unlikely to kill anyone.

 

[Tonygw]

LOL ooh I have opened a can of worms here..

I am merely stating what I hear.

You can argue against my comments as anti EV, parents should know better bla bla bla..

I am just saying it how I am hearing it.

 

[BTB 500]

How powerful the brakes are on a modern car is irrelevant as all modern cars have the braking power to easily reach the tyre limits..........what determines how fast they stop is the tyre choice (EVs tend to come with tyres designed for high range rather than high grip!!), rear to front weight transference and the mass of the car.....which is why on average EVs take a little longer to stop.... there is just more to stop!

I didn't think mass was a significant factor in stopping distances, provided the brakes are still able to apply enough force to stop the wheels. A heavier vehicle can brake harder before skidding ... the extra weight on the tyres gives more grip on the road surface. AFAIK heavy trucks take longer to stop because the brakes on those aren't capable of locking all the wheels (the load on the hubs would be immense). A BEV would also normally have a lower centre of gravity than an ICE vehicle, so there should be less weight transfer under braking.

I suspect a lot of it is down to the stock tyre profiles & compounds being optimised more for efficiency on EVs, to improve the published range figures.

 

[ALFAitalia]

Mass is a fairly important factor in stopping distances....cant beat basic physics......! If i threw a cannon ball at you and then the same size tennis ball which will you find easier to stop dead......

Factors Affecting Braking Distance (GCSE Physics) - Study Mind

In this GCSE Physics Revision Guide, you will find high quality Factors Affecting Braking Distance GCSE Revision Notes and Past Paper Questions

studymind.co.uk

GCSE PHYSICS - How does Mass affect the Braking Distance of a Car? - How does Doubling the Mass affect the Braking Distance of a Car? - GCSE SCIENCE.

How Doubling the Mass affects the Braking Distance of a Car

www.gcsescience.com

 

[BTB 500]

Mass is a fairly important factor in stopping distances....cant beat basic physics......! If i threw a cannon ball at you and then the same size tennis ball which will you find easier to stop dead......

Factors Affecting Braking Distance (GCSE Physics) - Study Mind

In this GCSE Physics Revision Guide, you will find high quality Factors Affecting Braking Distance GCSE Revision Notes and Past Paper Questions

studymind.co.uk

GCSE PHYSICS - How does Mass affect the Braking Distance of a Car? - How does Doubling the Mass affect the Braking Distance of a Car? - GCSE SCIENCE.

How Doubling the Mass affects the Braking Distance of a Car

www.gcsescience.com

I think that's wrong. Push an empty box along the ground, then fill it up with sand and try again.

The example you linked to assumes the same braking force is applied in all cases, which isn't what happens. Increasing the weight increases the amount of friction the tyres can generate on the road surface before they slip (skid). This means more braking force is possible, which offsets the fact that the heavier vehicle has more energy to lose at any given speed.

As mentioned I think the limitation on HGVs is that the wheels and brakes don't have the mechanical strength to handle those forces without something breaking. But that doesn't apply to cars, which are all capable of locking the wheels (if ABS allowed this).

 

[BTB 500]

I think that's wrong. Push an empty box along the ground, then fill it up with sand and try again.

The example you linked to assumes the same braking force is applied in all cases, which isn't what happens. Increasing the weight increases the amount of friction the tyres can generate on the road surface before they slip (skid). This means more braking force is possible, which offsets the fact that the heavier vehicle has more energy to lose at any given speed.

As mentioned I think the limitation on HGVs is that the wheels and brakes don't have the mechanical strength to handle those forces without something breaking. But that doesn't apply to cars, which are all capable of locking the wheels (if ABS allowed this).

Here you go ... the kinetic energy of a moving vehicle and the braking effect are both directly proportional to its weight, so one is directly offset by the other and weight is not a factor in the stopping distance equation:

Braking distance - Wikipedia

en.wikipedia.org

It's also stated that heavy trucks are an exception due to the limitations of their braking systems

The type of brake system in use only affects trucks and large mass vehicles, which cannot supply enough force to match the static frictional force.

 

[Bobby Dazzler]

LOL ooh I have opened a can of worms here..

I am merely stating what I hear.

You can argue against my comments as anti EV, parents should know better bla bla bla..

I am just saying it how I am hearing it.

I don’t doubt it at all. I’ve never heard that EVs are called “child killer cars” - or criticism of not running road safety adverts - but I can believe it as it’s the kind of thing that uninformed people might say.

Human instinct is to point the finger of “blame” at someone else rather than accept responsibility - and ideally a generic person or group - and it seems to be a strengthening trait in modern-day society.

It’s very much en-vogue to blame the Government for anything and everything so again not a surprise. Blame the Government that 2030 is too soon, then blame the Government for pushing it back to 2035, etc.

 

[Mactech]

However is lots of reports on braking (see Google!) EVs take LONGER to stop than ICE vehicles not shorter........but only by a few feet. How powerful the brakes are on a modern car is irrelevant as all modern cars have the braking power to easily reach the tyre limits..........what determines how fast they stop is the tyre choice (EVs tend to come with tyres designed for high range rather than high grip!!), rear to front weight transference and the mass of the car.....which is why on average EVs take a little longer to stop.... there is just more to stop! If they were identical apart from having a battery motor then they would stop in the same time.

Don't be too sure that because a tyre has lower rolling resistance and is for EV's that it has less grip to stop!


I'm just about to put Michelin e Primacy on my i3....which just happen to come out best of any tyre in wet braking
That's not really the reason I'm changing the perfectly reasonable Bridgestone tyres for these, I'm actually seeking a better ride, lower noise and better range.
Oh NO! lower noise ! I'm obviously now going to kill more school kids

 

[Flyinspanner]

The new top dog is the 1234-horsepower Lucid Air Sapphire.
View attachment 147306

Well that performance sounds amazing, especially in something that looks like it could be the new Accord/Passat!

It looks so ‘ordinary’ - not like some bewinged ducted, scooped pseudo Batcar - amazing that they’ve got that performance from a very standard looking car!


I wonder how it actually handles on a track, it’s one thing accelerating, but I wonder how it goes on an undulating road, grips in corners etc?

 

[ALFAitalia]

Just as badly as all the other EVs I would guess.....so that's heavy, clumsy and imprecise. Can't beat them there physics....and it weights 2375 kg!.....even more than the fatso new C63 hybrid!

 

[E55BOF]

Just as badly as all the other EVs I would guess.....so that's heavy, clumsy and imprecise. Can't beat them there physics....and it weights 2375 kg!.....even more than the fatso new C63 hybrid!

I recall a slalom course comparison test on Top Gear, Chris Harris driving all three cars, in which the Tesla was a touch quicker than the current Alfa Quadrifoglio...

I still don't want one, but it's not because of the handling or performance.

 

[Mactech]

Just as badly as all the other EVs I would guess.....so that's heavy, clumsy and imprecise.

That is exactly the opposite of my experience with the BMW i3 then! Make that light (1270 kgs with a c of g just above the floor), agile and very precise.
How many EV's have you actually driven?

 

[ALFAitalia]

I recall a slalom course comparison test on Top Gear, Chris Harris driving all three cars, in which the Tesla was a touch quicker than the current Alfa Quadrifoglio...

I still don't want one, but it's not because of the handling or performance.

Having so much more power will help of course......!!!...but you cant beat physics and weight affects handling on a proper track or twisty road above nearly everything else. Mactech above most others will know this. My 159 handled very well.....but not a patch on the on the previous far lighter 156 I had before. Imagine how much more nimble the Tesla would have been with the Quads light weight. I've not seen that test but was the Tesla a 4WD one?...which of course would help in a slalom too. Tesla weight 1,961–2,250 kg, quoted Quad weight 1540kg (but 1600 to 1630kg seems more like reality (typical ALFA weight claims!))....but still very light for the class and half a ton less than the T3.

That is exactly the opposite of my experience with the BMW i3 then! Make that light (1270 kgs with a c of g just above the floor), agile and very precise.
How many EV's have you actually driven?

Obviously there are exceptions....the i3 is a very light car by even ICE standards....so all you are doing is proving my point that weight matters! (You do have to put up with the odd people carriers looks and steering with no feel whatsoever though!!!)
I've driven quite a few....I still have lots of mates in the trade so still drive a lot of different new cars and get invited to model launches.....and I've driven quite a few customer EVs. Not found one that felt light and alive (not saying they are not out there).......but to 90% of owners this would not matter of course....same as a comparison between a C63 and a M3......they are different.....but most drivers wont be able to tell on there commute or holidays and people dont drive like road testers and most never go in a track!!
The weight thing is not so much an anti EV thing....just an anti weight thing........If I was in the market for a new fast saloon the 2 ton plus weight of the latest C63 would take it off my roadtest list before even driving it.......

 

[ChrisHGTV]

Bone conduction headphones are probably the best option if you must listen to music but want to retain situational awareness. I'm looking at getting some for Mrs BTB who currently jogs with conventional headphones on.

Ive got some that i use for running. They work well, and i don't get that irritating wind noise that my old in ear headphones were afflicted with (though they were cheapies)

 

[BTB 500]

Ive got some that i use for running. They work well, and i don't get that irritating wind noise that my old in ear headphones were afflicted with (though they were cheapies)

Thanks for that - it's Mrs BTB's birthday in a few weeks so I'll buy her some to try. She did get some for her dad last year, who's a keen cyclist.

 

[ALFAitalia]

I had to google what Bone conduction headphones were as they are new to me! They don't get good reviews for sound quality (obviously I guess) as well as they can cause hearing loss if used improperly, headaches and vertigo! Its not selling them to me to be honest!!!

 

[ChrisHGTV]

I had to google what Bone conduction headphones were as they are new to me! They don't get good reviews for sound quality (obviously I guess) as well as they can cause hearing loss if used improperly, headaches and vertigo! Its not selling them to me to be honest!!!

The sound quality isn't as good as conventional headphones but for running etc they're more than good enough. For sure they're not audiophile quality though. Ive never had any discomfort or issues.

 

[BTB 500]

I had to google what Bone conduction headphones were as they are new to me! They don't get good reviews for sound quality (obviously I guess) as well as they can cause hearing loss if used improperly, headaches and vertigo! Its not selling them to me to be honest!!!

Better than being run over and killed by an evil EV sneaking up behind you though