OT: Vehicle emissions and costs

In message , harry writes

That is fine as far as it goes, but it is dated 2004, and only really relates to CO2. To me the only interesting confirmation of my suspicions was that it appears to show that the imposition of low speed limits (eg

What I was after was some real data that analysed the exhaust from various types of engine and listed amounts of each pollutant detected.

We just seem to be jumping from one bandwagon to another without much in the way of real data to go on.

I see in he paper today that someone has said that you are breathing less pollution inside a diesel car than sitting on a bus. All this might seem to suggest is that the car's pollen filters are doing a good job.

That might be true of particulates, but not NO2.

Even a modern diesel engine with emit many times more NO2 than a less modern petrol engine.

Do you have evidence of that?

Most petrol cars don't have a working cat for most of their urban motoring.

Such information is probably very, very secret.

In reality, all vehicle manufacturers aim to comply with the exhaust emissi ons laws, which become more stringent every few years. Recent experience ( VW) has shown that some manufacturers are better at meeting the law than ot hers, but it seems clear that there's little incentive for anybody to produ ce internal combustion-engined vehicles that are significantly cleaner than the law demands. Particularly as the law is tightened every few years.

So, I think it's reasonable to assume any vehicle will (just) meet the exha ust emissions limits in force at the time it was manufactured. The tables at the end of the article below are a good summary:

Those figures are in grammes per kilometer driven on the mandated test driv e cycle. They show that for the current law (Euro 6 - since 2014), petrol and diesel cars are pretty similar. That wasn't the case 10 or 15 years ag o, when Euro 3 or Euro 4 laws were in place.

We can see from

There is some in the open literature but the makers are basically designing their engines to beat the tests (some going so far as to detect the test regime and alter engine behaviour accordingly).

This is a start but I have no idea how reliable it is:

Much of the research work is behind a paywall though eg.

Be a very expensive things to do properly and independently.

Most vehicle emissions are 'self certificated'. And we all know about that.

NOX emissions is what killed lean burn petrol engines. Most modern petrol engines with a cat. when running at normal temperature actually remove NOX from town atmosphere. In other words, less comes out of their exhaust than went in to the engine.

Bollox. Most have their cat. fully functional in less than a mile from cold.

If you ran the petrol engine on LPG you would get water and CO2, a tiny amount of CO and a very tiny amount of unburnt hydrocarbons, and that's without a cat. So the government destroyed conversion market by phasing out the fuel duty differential.

Apparently you also get NOX, though not as much as from a petrol engine.

Robert

How does one get nox from propane? (C3H8)

In message , "Dave Plowman (News)" writes

The problem with London is London itself. Why does everyone have to cram into and pollute one area in this "digital age"?

But I thought I'd look at the particulate data for tyres and there's this pdf

which says

As shown in the above analysis, tyre dust emissions due to tyre protector wear (in g/km) significantly (by 6-7 times) exceeds emissions of particulate matters with exhaust gases of passenger car engines. Emissions of firm particles as a result of wear of tyres protector on vehicles of up to 3.5 tons GVW reach 0.,051 g/km, which already almost 5 times exceeds the provisions of the UN Regulation No. 83 on emissions of particle matters for the engines installed on those vehicles. Comparison for commercial vehicles cannot be made due to difference in test methods and estimation of emission value in g/kWh for compression ignition engines. However, it can be expected that tyre deterioration particle emissions should exceed engine particle matter emissions by

Same way as from octane (C8H18), ie petrol - heat air (N2 and O2) up together. It forms near where the flames are.

You get NOx from very very hot compressed AIR which contains nitrogen and oxygen.

The more air in the mix (lean burn) and the higher the temperature and pressure (the more efficient the engine is) the more NoX you get.

If there is less air, the engine is less efficient and nearly all the oxygen gets used up in burning the fuel, and some part or unburnt fuel is left over.

Running the engine of pure oxygen would work, but would you want to drive a car with a tank of oxygen as well as a tank of fuel?

If fuel cells were more efficient at high power, they might work

But then you would still be carrying tanks of hydrogen and oxygen..

From the nitrogen in the air, bozo.

So it doesn't come from the propane, bozo. (Thanks to the others for the intelligent responses).

And off to the 'tard farm you go, with all the other windowlickers.