7
votes
Accepted
What measures could be taken to decrease the air pollution in a big city?
To encourage people to not use of purchase cars develop a public transportation system that is easily accessible by the to public and caters to the needs of the public so that people will use it. ...
- 3,507
7
votes
Accepted
Does 1 container ship really pollute as much as 50,000,000 cars?
It depends on how you define "pollution".
Cargo ships use some of the dirtiest fuels available: bunker fuel is basically what's left over after you refine all the good stuff out of crude oil....
- 598
6
votes
Accepted
Does putting an automatic car in neutral when stopped help save petrol?
According to this answer over on mechanics.SE, below a certain engine RPM, your vehicle automatically disengages the torque converter. That is to say, when stopped, there isn't a fundamental ...
- 11.8k
6
votes
To what extent (if any) are electric vehicle batteries recyclable?
Li-Ion batteries are worth recycling just for the lithium in them. This material can be re-refined, and made into new batteries. In this use they should show similar cost savings to recycled vs new ...
- 7,197
6
votes
To what extent do CO2 emissions from motor vehicles vary?
CO2 is produced by burning the carbon in the fuel, so if your driving style causes you to use twice as much fuel, you will produce twice as much CO2. Driving aggressively can have a big impact on ...
- 303
6
votes
Which countries, regions, or cities have set a date to ban the sale of gasoline and diesel vehicles?
The best list is probably wikipedia: Phase-out of fossil fuel vehicles
There is a good review from the World Economic Forum here, dated 2017, which discusses some of the different approaches taken, ...
- 1,001
5
votes
Impact on environment: a million horses vs a million cars
I think the main problem is that commuting is almost never "eco-friendly". There's a lot of energy that's needed to carry your behind (and your carriage) from your home to your workplace.
I think the ...
- 5,963
5
votes
Accepted
How feasible would a gas-powered electric-engine based car be?
It would work, but there isn't much reason to do it. If you do this without batteries, you are giving up most of the potential advantages.
If you simply have an internal combustion engine (petrol or ...
- 3,680
5
votes
Why is the private car still more popular over other forms of transport in the USA?
It is well within any government's power to tax the private automobile into the ground by raising taxes exponentially on the private use of fuel.
(...)
Not a single major politician, not a single ...
- 2,535
4
votes
Accepted
The more miles a car drives, the more economical battery packs become?
The immediate previous sentence says:
The other unknown that BNEF considers is the rise of autonomous cars and ride-sharing services like Uber and Lyft, which would all put more cars on the road ...
- 328
4
votes
What measures could be taken to decrease the air pollution in a big city?
Plant a lot of trees -- assuming you mean partciulate pollution: See for example Estimating the removal of atmospheric particulate pollution by the urban tree canopy of London, under current and ...
- 2,107
4
votes
Accepted
How efficient are tiny cars compared to others?
In the USA the Daimler/Mercedes "Smart" Fortwo car is the obvious choice, rated at 41mpg on the highway. Those look silly but are quite safe and very fuel efficient, as well and being ridiculously ...
- 3,875
4
votes
How feasible would a gas-powered electric-engine based car be?
The concept has been used in heavy duty mining trucks for decades. Diesel powered locomotive engines power an electric generator that then powers electric motors located on the rear axles of the ...
- 3,507
4
votes
Accepted
Why are electrical cars encouraged but is electrical heating discouraged?
There are several reasons why a policy of encouraging electric cars, but discouraging electric heating, might make sense. I can't answer for the specific case of Belgium, which currently has some ...
- 14.7k
4
votes
To what extent (if any) are electric vehicle batteries recyclable?
It appears that currently (late December 2020), lithium from batteries is not recycled, because it is only worth 6 euro per kg (9 USD per kg). The only metals recovered from Li batteries are the ...
- 3,507
4
votes
Are there any unsustainable supply-chain issues unique to hydrogen fuel cell vehicles?
The favored anode catalyst in a hydrogen fuel cell is platinum(1) or another platinum-group element (e.g. palladium). The catalyst is required in small quantities for an individual fuel cell but of ...
- 1,604
3
votes
Can alloy wheels (for a car) pay for themselves through fuel savings?
Theory
The calculation in the other answer is rather naive. I haven't done the calculation myself, but there are a few things to consider. First of all, lighter wheels mean more than just lower ...
- 131
3
votes
Why are electrical cars encouraged but is electrical heating discouraged?
There are a couple of good answered already, but here's another perspective (who said a question can only have one right answer!).
In a possible future world where electricity generation is ...
- 3,680
3
votes
Why are electrical cars encouraged but is electrical heating discouraged?
The biggest reason is why it is being used. Converting combustion heat into electricity and then converting electricity back into heat is highly inefficient. Better to just create the heat by ...
- 187
3
votes
Why are electrical cars encouraged but is electrical heating discouraged?
The first part of your question is about where pollution happens as much as about pollution reduction. Cars emit pollution where people are, while electric generators can be built further away from ...
- 3,875
3
votes
Fuel efficiency when decelerating on a hill
Generally a driver doesn't know the exact angle of the hill at any point in time, nor do they generally know the exact combination of gear and gas-pedal that will be the most efficient.
Maybe some ...
- 8,745
3
votes
How to prevent older Diesel cars from emitting NOx, dust and smell?
By crushing the car and recycling the metal. That's how.
Diesel cars are awful and there's pretty much nothing anyone can do about it, if the recent VW diesel cheating scandal hasn't already made ...
- 426
3
votes
What measures could be taken to decrease the air pollution in a big city?
This brochure of the European Environmental Bureau gives 12 good tips to reduce air pollution in a city. Here a summary and some extra information I added:
Create Low Emission Zones (LEZ): charge or ...
- 179
3
votes
The more miles a car drives, the more economical battery packs become?
The article is considering the total costs of ownership of electric vs internal combustion engined (ICE) cars, including purchase and running costs. One of the benefits of electric cars is that fuel ...
- 3,680
3
votes
Accepted
What are the carbon emissions from the manufacture of the hybrid components of a Prius?
Update. In my original answer I inadvertently divided at one point when I should have multiplied -- I found the mistake thanks to comments from Frank and THelper. So here's a new tl;dr:
By mile 4,000 ...
- 11.8k
3
votes
To what extent (if any) are electric vehicle batteries recyclable?
Battery recycling today is handled by 3rd parties. This leads to issues of economic value on materials extracted since they must cover a large variety of battery types and cannot specialize on any one....
- 191
3
votes
Does Start / Stop technology in cars have an impact on air quality and by how much?
Idling is particularly bad for NO2 emissions, which are a major concern for air quality. Here's an old paper showing that an idling engine emits more NO2 than one driving at 40 km/h, despite emitting ...
- 2,107
3
votes
Accepted
EU Real Driving Emissions testing (RDE) - does it factor in real driver behaviour and the inefficient driving habits they often exhibit?
Under RDE [Real Driving Emissions test], a car is driven on public roads and over a wide range of different conditions..... Conditions include:
Low and high altitudes
Year-round temperatures
...
- 14.4k
3
votes
How to prevent pollution caused by a taxi rank? Is there a solution to the 'edging forward' cost of cars in a queue?
Have the taxis (*) fill two or more lanes (| |) leading to the station, with one ready to pick up the next passenger (:)) coming out.
|*|*|
|*|*|
|*|*|
|*|*|
:) *
Once that cab ...
- 11.8k
3
votes
How to prevent pollution caused by a taxi rank? Is there a solution to the 'edging forward' cost of cars in a queue?
A variant of the system suggested by @LShaver, would be to use the numbered ticket system sometimes found in supermarket deli counters. Each arriving taxi takes a sequentially numbered ticket (which ...
- 773
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