Also many of the big diesels in buses and lorries have been converted to having wee wee injection so the NOX is about a tenth of wiesel without SCR

Does it really help?

Another thread somewhere on this site linked to a test of a SCR fitted merc.

The nox emissions skyrocketed as soon as the ambient temprature dropped.

At 5 degrees the emissions was 20x greater than at the 22 degrees used in the lab tests.

Does it really help?

Another thread somewhere on this site linked to a test of a SCR fitted merc.

The nox emissions skyrocketed as soon as the ambient temprature dropped.

At 5 degrees the emissions was 20x greater than at the 22 degrees used in the lab tests.

 

Quite right and we actually knew this when cats came in a quarter of a century ago and the emission systems need to be kept close to the Normal Temperate and Pressures else the do not work without warming sub-systems.  You will know we do this for cold climate fuel system as we did in Canada when temperatures hit -40.

 

Petrol and gas has much less problems at lower temperature than wiesel does even with pre-heaters are the slightly lower thermal efficiency of petrol engines actually help the warm up of the engine and the post combustion exhaust gas systems get up to working temperature quicker of course.   

Edited 14 March, 201610 yr by lol-lol

Does it really help?

Another thread somewhere on this site linked to a test of a SCR fitted merc.

The nox emissions skyrocketed as soon as the ambient temprature dropped.

At 5 degrees the emissions was 20x greater than at the 22 degrees used in the lab tests.

That wasn't 'cos they didn't or wouldn't work at the lower temps, is was a 'workaround' the test rules to reduce adblu usage on the road, wasn't it?

Anybody would think a certain person in this thread just hates diesels and is trying desperately to push petrol as they own one. perhaps they secretly regret buying a petrol?

That wasn't 'cos they didn't or wouldn't work at the lower temps, is was a 'workaround' the test rules to reduce adblu usage on the road, wasn't it?

 

Not only for adblue usage it was for reliability of the system and capacity of the SCR system. Merc have already showcased the solution but it has two SCR chambers, pre-cat, multi EGR system and on some models a NOx trap. Adds an additional £1500 premium over the current diesel per unit.

 

Mercs current system was disabled below 10 degrees putting out 40 times more NOx than the current limit.

Anybody would think a certain person in this thread just hates diesels and is trying desperately to push petrol as they own one. perhaps they secretly regret buying a petrol?

 

For me it's the opposite, my car is a modern 2.0CR TDi but I'd rather have a TSi or other turbo petrol.

 

My mileage forces me down the diesel route because of the economy but If I was doing less miles or the tax situation changed I'd be happy to swap to petrol.

 

Lee

The problem is short of hydrogen cars what's the answer for heavier vehicles, 4x4s, vans, lorries etc? 

 

Batteries are an environmental nightmare and at best only push the problem on to an almost overloaded and not very clean power grid.  Petrol whilst better for small cars (they should never have been diesel imho) just doesn't seem practical for bigger vehicles.

 

Whilst there shouldn't be anywhere near as many big vehicles like 4x4 "chelsea tractors" on the road and "bigger" cars are getting lighter I can't see us getting rid of the need for vans and lorries any time soon.

 

LPG seemed like a nice option for a while but appears to be disappearing again.

There are possibilities for larger vehicles such as this from the good old US of A ;

http://www.wrightspeed.com/technology/the-fulcrum/

EGR's increase CO2 production but lower NOx and also shorten the life of the engine/vehicle.

Net result is far more pollution and addditional energy expended in making the vehicle/parts per year of it's life.

Hybrids shortly followed by Hydrogen Fuel Cells seem to be the way forward.

That wasn't 'cos they didn't or wouldn't work at the lower temps, is was a 'workaround' the test rules to reduce adblu usage on the road, wasn't it?

I dont know.

The one thing I do know, is that its more or less always in the winter that the airquality gets bad around here.

Cities like Bergen sometimes have reduce traffic because of emissions, and does it by only allowing reg numbers ending with Odd numbers to drive one day, and even numbers the next.

Although much of the pollution comes from ships docked there.

I dont know.

The one thing I do know, is that its more or less always in the winter that the airquality gets bad around here.

Cities like Bergen sometimes have reduce traffic because of emissions, and does it by only allowing reg numbers ending with Odd numbers to drive one day, and even numbers the next.

Although much of the pollution comes from ships docked there.

 

That seems like a very sensible way to reduce traffic, we should copy that here.

 

I think the reason that pollution is worse in winter is to do with the vertical stability of the atmosphere and its relation to temperature and solar heating (or not) of the earth's surface, plus moisture content. 

In unstable conditions, pollution escapes upwards and then dispersed to other locations, in stable conditions it just sits above the ground near to where it's generated.

 

From Wiki:

"The combination of moisture and temperature determine the stability of the air and the resulting weather. Cool, dry air is very stable and resists vertical movement, which leads to good and generally clear weather. The greatest instability occurs when the air is moist and warm, as it is in the tropical regions in the summer. Typically, thunderstorms appear on a daily basis in these regions due to the instability of the surrounding air."

I dont know.

The one thing I do know, is that its more or less always in the winter that the airquality gets bad around here.

Cities like Bergen sometimes have reduce traffic because of emissions, and does it by only allowing reg numbers ending with Odd numbers to drive one day, and even numbers the next.

Although much of the pollution comes from ships docked there.

 

They tried that in Naples years ago.  Everybody just had 2 cars........

Edited 14 March, 201610 yr by keystonedriving

They tried that in Naples years ago.  Everybody just had 2 cars........

 

It was used in Paris a few months ago and has been used in Athens several times over the last few years.  It penalizes those who do not have two cars or have two cars with both odd or even registrations.  Must reduce traffic somewhat, encourage lift sharing, use of motorcycles and public transport.

 

I am always amazed how much of a system the London LEZ is and how that works.  Durham also started this and Milan too I gather.  More cities likely to and London's system expanded. 

They tried that in Naples years ago. Everybody just had 2 cars........

Thats what happened here as well.

Will be interesting to see how they fare with an eventual dieseban, and how it will be enforced.

Thats what happened here as well.

Will be interesting to see how they fare with an eventual dieseban, and how it will be enforced.

 

I think Governments like that idea better because it means more revenue for their tax receipts and not less.

 

In the UK we already have a very large number plate recognition system on many roads to charge tolls and it would be expected that this is what will be used to charge those vehicles above the pollution criteria ie diesels without SCR a charge of £20 is on the books for entering the big cities.

 

This therefore does not ban these cars absolutely but discourages their regular use in cities affected by NOX and PM pollution at critical times and seasons but does not mean citizens, could be doctors and nurses needing to attend a hospital for work, from accessing the city.

 

 it would be expected that this is what will be used to charge those vehicles above the pollution criteria ie diesels without SCR a charge of £20 is on the books for entering the big cities.

 

 

But there's no way of identifying which cars have SCR or not. Just Euro 5 and Euro 6.

 

And as we know having SCR fitted doesn't really mean limits are met on the road, especially when it's cold on some GM and Merc models.

 

The London think tank are already suggesting all diesels get charged unit the 2017 standards are introduced.

 

Lee

It's a "Think Tank" that has no influence or responsibility - they can claim anything they want and this is just a bit of attention seeking.

 

 

The problem with this one is they get listened to, they came up with the Police Commissioner idea. 

 

 

In the UK we already have a very large number plate recognition system on many roads to charge tolls and it would be expected that this is what will be used to charge those vehicles above the pollution criteria ie diesels without SCR a charge of £20 is on the books for entering the big cities.

 

 

 

Large scale tracking of numberplates could be illegal depending on how it is done. It can be considered surveillence which falls under RIPA/RIPSA and can be a breach of human rights legislation.

One police force already fell foul of this when they ringed a town with CCTV. Can't remember which one now.

For me it's the opposite, my car is a modern 2.0CR TDi but I'd rather have a TSi or other turbo petrol.

 

My mileage forces me down the diesel route because of the economy but If I was doing less miles or the tax situation changed I'd be happy to swap to petrol.

 

Lee

 

I would've happily ditched the Octavia if I could've gotten a decent amount for it.

As it stands though vehicle condition isn't good enough to get my intial investment back (or anywhere near enough) to make it worth me buying a different car.

 

Better the devil you know.

The problem is short of hydrogen cars what's the answer for heavier vehicles, 4x4s, vans, lorries etc? 

 

 

 

Why do you think they can't use Hydrogen/ Fuel cells?

Edited 15 March, 201610 yr by io1901

Large scale tracking of numberplates could be illegal depending on how it is done. It can be considered surveillence which falls under RIPA/RIPSA and can be a breach of human rights legislation.

One police force already fell foul of this when they ringed a town with CCTV. Can't remember which one now.

 

 

Isn't this how the Congestion charge works in London?   It tracks the plates and if payment hasn't been made it sends out a fine.

Not directly related but may be of some interest:-

 

 Hydrogen Powered Generators

Edited 15 March, 201610 yr by io1901

To be honest, if they start charging £800 for the tax on mine, I'll just stop paying it. From experience, the fine's generally less than a year's tax, worst case, they impound a car that didn't cost £800.

Why do you think they can't use Hydrogen/ Fuel cells?

Sorry maybe wasn't clear. When I said short of, I meant unless we can use Hydrogen.

Fuel cells seems to be the only practical solution for high energy high speed recharge needed for large heavy vehicles.

Hyundai have an ix35 with hydrogen out but it's just waiting on a distribution network. I've not seen anyone else making one yet.

Edited 15 March, 201610 yr by gullyg

With the low oil prices there isn't much of incentive to switch unless Governments go down the Tax route.

Isn't this how the Congestion charge works in London? It tracks the plates and if payment hasn't been made it sends out a fine.

As far as I know this is how it work in Durham and London. Not sure if the same in Paris recently, Milan you need an Ecopass to be in the city at these times. With Delhi you just get stopped by the cops and issued a fine if you are in the city designated area with the wrong registration ie odd or even of the other days and they issue you with a penalty fine.

The London system costs around £100M per annum to setup and run but raises twice that. London being a supersized city (only Moscow in Europe is a similar size) can run a big surplus but most of the European cities which find it hard to do much better than cost neutral, even a city like Birmingham with a population bigger than many capital cities.

We have it on the Queen Elizabeth Thames Crossing at Dartford too of course.

Edited 15 March, 201610 yr by lol-lol