Environmental issues are of growing concern. For decades now the scapegoat remains to be the car. Cars pollute. It is a fact, butare they as bad as it is made out.
Let's look from a different perspective. Before China became the economical power it is the US of A was the largest polluter in the world with a share of 25% but only under 4% of the worlds population. China is catching up since.
Since the US drivers do not do 25% of the worlds driving pollution can not solely stem from cars. If it were so the Yanks would drive on average about 6 times as much as anyone else does.
Let.s put this aside and look at some of the environmental measures taken since green thinking was invented.
Although not intended to be an environmental measure, the fuel injection was a step forward. However at the time the cat was invented the slogan was that HCs and CO is lethal and it would be necessary to curb them by the use of a cat for a better environment.
To put it in easy terms, the cat was a total failure.
First of all the NOx broken down by nature in less than 4 hours. CO is not stable and oxydises into CO2. HCs can be controlled in the combustion process.
As the cat has got a 'working window' it needs to reach a certain temperature and at the same time must not exceed the upper threshold either. Going beyond it might eventually lead to a cat 'death'. Problem is that the cat does not die. It just doesn't do what the cat is made for. It will do a reverse catalysis and make things worse. In extremely cold as well as very hot places this always will be a problem.
This is by far not the end of the problems with a cat. It also produces Arsenic. What cats create annually in the whole of India currently is enough to kill adults by the lakh if accumulated and administered potion by potion. Other by products are H2SO3 and H2SO4 in traces. Good for our lungs and corrosive too!
Additionally the cat is an unwanted contraption in the exhaust pipe increasing the fuel consumption slightly due to pressure build-up. This will heavily increase as in many cars the cat clogs or partly melts. Further, the cat requires mid range a rather lean fueling, which means the power to drag ratio increases unfavorably increasing fuel consumption further.
Till date nota single study has proven to be an environmental benefit. All 'studies' available are speculative and brilliantly misleading worded. But it has been a great financial success.
To sum it up, the cat would get zero out of ten for environmental reasons.
It is about time that cats are made redundant. The practise has proven that theory does not work, when key issues have been left out. The cat has increased the carbon foot print on every car.
Next is the Diesel particulate filter.
In theory a good idea. However, it begs the question why first creating the particles? The technology is available. The DPF is a particle trap, which builds up unwanted pressure. This is no good news for economy and increases the carbon foot print. Additionally a lot of fuel is used to burn of the particles once saturation point is reached. When removing the DPF fuel efficiency increases on average by 8% and performance increases from 5 to 12% depending on the engine.
TBC