20mph Wales

victor2

Herzlos said:

MouldyOldDough said:

HHarry said:

MouldyOldDough said:

born_again said:

MouldyOldDough said:

https://mol.im/a/12393711
I can't see this actually happening.....
It's going to cause more pollution due to low gear 
More noise due to high revs 

Does not compute
Unless you are a idiot & sit in 1st gear. Plenty or 20 zones round here on residential streets. Causes no problems & makes it safer for all road users.

Yes it does - if your car doesn't like top gear at 20mph (and I don't know what car does) - and remains in a lower gear - the engine will be turning at faster revs - than it would in top gear - so the exhaust  will be pumping out more noxious gases (per mile) !

Simple

I am not denying the safety side of it !!!!

You may have to use a lower gear, but you are travelling at a slower speed, so the rpm isn’t necessarily more than 30mph in top.

HHarry said:

MouldyOldDough said:

born_again said:

MouldyOldDough said:

https://mol.im/a/12393711
I can't see this actually happening.....
It's going to cause more pollution due to low gear 
More noise due to high revs 

Does not compute
Unless you are a idiot & sit in 1st gear. Plenty or 20 zones round here on residential streets. Causes no problems & makes it safer for all road users.

Yes it does - if your car doesn't like top gear at 20mph (and I don't know what car does) - and remains in a lower gear - the engine will be turning at faster revs - than it would in top gear - so the exhaust  will be pumping out more noxious gases (per mile) !

Simple

I am not denying the safety side of it !!!!

You may have to use a lower gear, but you are travelling at a slower speed, so the rpm isn’t necessarily more than 30mph in top.

Slower speed = less distance per g of noxious gas
To get from a to b will take longer so more gas emissions 

Only if engine speed is directly related to fuel consumption like in an old carburetor engine. With modern computer controlled injection. Slower speed will mean less fuel used per distance unless you're thrashing it i.e. 20mph in 1st.

Sounds like an "informative" project for the old Top Gear team. 1 litre of fuel and James May at 20mph, Jeremy Clarkson at 120mph and Richard Hammond in a rocket powered vehicle (that won't even leave the start line)... 

WellKnownSid

MouldyOldDough said:

Slower speed = less distance per g of noxious gas
To get from a to b will take longer so more gas emissions 

You seem super concerned by all of this.  Might I suggest either moving from Wales or buying an EV?

Herzlos

I tried an experiment on the drive home from work earlier. Constant 20mph on a straight section of road on a consistent gradual climb, using 3rd and then 4th gear. Both gave me 62mpg but in 4th the car struggled a bit and told me to change down.

Next time it's quiet I'll try the same at 30mph. From memory I think I usually get mid 40's there at 30mph.

silvercar

WellKnownSid said:

MouldyOldDough said:

Slower speed = less distance per g of noxious gas
To get from a to b will take longer so more gas emissions 

You seem super concerned by all of this.  Might I suggest either moving from Wales or buying an EV?

Driving an EV, it is annoying seeing signs that speed limits have been imposed in order to reduce emissions - that's why I bought an EV in the first place, not to toodle along at 20mph!

prowla

DE_612183 said:

prowla said:

Wales is a funny old place - the locals tell people not to go there and then they complain that tourism is struggling.

Now there's a new national speed limit, so things will take longer; I expect there'll be complaints that deliveries are taking too long or cost more.

Generalisations are funny old things....

Usually...

Herzlos

silvercar said:

WellKnownSid said:

MouldyOldDough said:

Slower speed = less distance per g of noxious gas
To get from a to b will take longer so more gas emissions 

You seem super concerned by all of this.  Might I suggest either moving from Wales or buying an EV?

Driving an EV, it is annoying seeing signs that speed limits have been imposed in order to reduce emissions - that's why I bought an EV in the first place, not to toodle along at 20mph!

Just think how quickly people would drop all the FUD about EV's if they could travel at 30 in a 20 zone!

WellKnownSid

silvercar said:

Driving an EV, it is annoying seeing signs that speed limits have been imposed in order to reduce emissions - that's why I bought an EV in the first place, not to toodle along at 20mph!

I think the “most children survive a 20mph collision” argument is the real reason.  Reduced emissions is an added bonus.

My late Mother was a police class one driver so I have always been taught to do no more than 27mph in a 30 - and I consistently get overtaken, sometimes in quite dangerous manoeuvres.  I have noticed that in 20mph limits (at least around here) the propensity for drivers to overtake appears to be far far far less.

Martyn1981

Herzlos said:

silvercar said:

WellKnownSid said:

MouldyOldDough said:

Slower speed = less distance per g of noxious gas
To get from a to b will take longer so more gas emissions 

You seem super concerned by all of this.  Might I suggest either moving from Wales or buying an EV?

Driving an EV, it is annoying seeing signs that speed limits have been imposed in order to reduce emissions - that's why I bought an EV in the first place, not to toodle along at 20mph!

Just think how quickly people would drop all the FUD about EV's if they could travel at 30 in a 20 zone!

If you really want to upset the apple cart, then on motorway sections with 3 or more lanes, make the outside lane BEV only and 70mph, whilst restricting ICEV cars to the same 60mph rule as lorries and vehicles towing. I think there have been suggestions along these lines, but only at the lightest level, possibly even lifting the outside/BEV lane to 80mph.

But just to stress, this is only an idea that has been pondered, I don't think there are any plans yet, and probably not a large enough BEV fleet yet, to make it viable ...... yet?

But silvercar has a point about the 'local emissions speed restrictions', there are several in S. Wales reducing 70mph sections to 50mph, and it is a tad annoying when driving a BEV.

ElefantEd

Personally I wouldn't want to drive my EV at 80mph, it really kills the range. I'd be happier if the speed limit was reduced to 60mph for everyone as this would be effective at reducing emissions.

20mph in an EV is extremely efficient, though slightly tedious on roads that don't really require it (eg. wide roads with good visibility that don't have houses alongside). There have been 20 zones in the Scottish Borders and Edinburgh for a while now, in reality any extra time taken is quite small; casual observation suggests that while not everyone obeys them strictly, typical speeds of those breaking them are less than 30, whereas when they were 30 limits some drivers went at 40.