Recall 5c back to factory for "modify engine exhaust management "

[Moro]

For petrol vehicles, these are dispproportionate reactions to the VW scandal; but it is a potentially serious problem for diesels I think, but not  for engines though.

My 2013 GTI DSG did an actual over 43mpg at a rather boring average of 41mph on a rather tiresome and quite often stopped (including engine) on an A3/M25/M1 return journey of over 200 miles yesterday...

Even if there is a petrol engined scandal to follow, for me I am sure no degree of faking of emissions and consequent fuel consumption could have been involved with these figures.

[Bungleaio]

I have owned a 2.5 litre Impreza that managed an average of 18mpg and a 4.2 litre petrol V8 range Rover that did 14mpg.

Green credentials weren't my highest priority when I was considering the GTI 

[monkeyhanger]

So my Gti built and  in transit (  stage 5a) and now sent back to factory for a modification to engine exhaust management.So not only diesels affected by engine cheat. Wonder how long I will have to wait for the car now.

Add 2 and 2 to get 5.

Very much doubt that your exhaust management recall is down to NOx emissions cheating. It is a diesel only problem.

Diesel auto-ignites at around 800C. Petrol is ignited under spark at around 130C, max internal temp of a cylinder in a petrol engine is around 250C, around 800C in the diesel. NOx is produced by the presence of an excess of Oxygen and Nitrogen from the air drawn in and subject to very high temperatures and pressures. The combustion conditions of a petrol engine don't lend themselves to copious NOx production.

Nitrogen in most conditions is considered inert - that's why there's so much of it in our atmosphere, It takes extreme conditions to make nitrogen containing compounds from atmospheric Nitrogen - Diesel engines provide those conditions, petrol engines don't.

Also petrol engines don't draw air in at a massive excess to that needed for the amount of oxygen to combust the fuel into water and carbon dioxide. More Nitrogen + higher temperature + higher pressure = more NOx.

As UK cars are taxed on their CO2 output, I can't see anyone facing a tax hike on their cars.

[Bungleaio]

I thi :roll eyes:nk someone hasn't read the whole thread 

[monkeyhanger]

I thi :roll eyes:nk someone hasn't read the whole thread 

If that's for my benefit then it has been mentioned by other posters that petrols shouldn't be affected, but I posted above to explain why Petrol engines make far less NOx.

[GTI_Ant]

I don't see why petrol motors should be affected.  The diesel market in the US is only about 3% (50% in the UK) as there isn't the same cost incentive for ownership over there.  So diesel cars are being pushed as "green" instead.  Whilst the CO2 emissions are slightly lower, it seems very difficult for manufacturers to avoid the clouds of NOx and carcinogenic oil-coated soot etc that we see every day over here.  Petrol cars don't have this issue.

[monkeyhanger]

I don't see why petrol motors should be affected.  The diesel market in the US is only about 3% (50% in the UK) as there isn't the same cost incentive for ownership over there.  So diesel cars are being pushed as "green" instead.  Whilst the CO2 emissions are slightly lower, it seems very difficult for manufacturers to avoid the clouds of NOx and carcinogenic oil-coated soot etc that we see every day over here.  Petrol cars don't have this issue.

Agree with you entirely on the Nox. The EU6 emissions targets specific to NOx is easily achievable for petrol engines, for diesels however, the NOx target for EU6 is a big drop from EU5 targets, which were a challenge to meet in the first place.

The DPFs do a good job in reducing soot, and in fact as petrol cars start behaving more like diesels (direct injection), they are more likely to emit soot of their own, smaller particulates that have the potential to be more harmful than those from diesel (more easily breathed into the lungs, and more mobile in the air), yet have no current requirements for a DPF. Cars like the 7R have direct injection, but also a post main injection "wash" indirect injection. This helps reducing the particulates and prevents the engine from coking up. Cars like the latest Mini generation are direct injection, but without that "wash" injection to clean things up - you can see reports of those engines needing decoking.

Cars aren't green, but they can be at their greenest when properly maintained. Pre-DPF diesels are absolutely filthy. More should be done to incentivise taking those off the road. Similarly a misfiring, badly maintained petrol car will be spewing out unburnt Benzene (used as an anti-knock agent, one of the most potent carcinogens there is) and vapourised fuel.

Seems like a typical Daily Mail story that has been blown up. If (I say more like "when") the other companies are caught at it, this will blow over and we will get some emissions testing reform.

For the litigation eager Yanks, they will be looking to batter the non-domestic marques to protect their own (Ford, GM, Chrysler etc.). With their fuel prices, a diesel in the US seems utterly pointless unless you're talking a big diesel V6/V8 4x4 anyway.

[Jackie Treehorn]

I don't see why petrol motors should be affected.  The diesel market in the US is only about 3% (50% in the UK) as there isn't the same cost incentive for ownership over there.  So diesel cars are being pushed as "green" instead.  Whilst the CO2 emissions are slightly lower, it seems very difficult for manufacturers to avoid the clouds of NOx and carcinogenic oil-coated soot etc that we see every day over here.  Petrol cars don't have this issue.

Agree with you entirely on the Nox. The EU6 emissions targets specific to NOx is easily achievable for petrol engines, for diesels however, the NOx target for EU6 is a big drop from EU5 targets, which were a challenge to meet in the first place.

The DPFs do a good job in reducing soot, and in fact as petrol cars start behaving more like diesels (direct injection), they are more likely to emit soot of their own, smaller particulates that have the potential to be more harmful than those from diesel (more easily breathed into the lungs, and more mobile in the air), yet have no current requirements for a DPF. Cars like the 7R have direct injection, but also a post main injection "wash" indirect injection. This helps reducing the particulates and prevents the engine from coking up. Cars like the latest Mini generation are direct injection, but without that "wash" injection to clean things up - you can see reports of those engines needing decoking.

Cars aren't green, but they can be at their greenest when properly maintained. Pre-DPF diesels are absolutely filthy. More should be done to incentivise taking those off the road. Similarly a misfiring, badly maintained petrol car will be spewing out unburnt Benzene (used as an anti-knock agent, one of the most potent carcinogens there is) and vapourised fuel.

Seems like a typical Daily Mail story that has been blown up. If (I say more like "when") the other companies are caught at it, this will blow over and we will get some emissions testing reform.

For the litigation eager Yanks, they will be looking to batter the non-domestic marques to protect their own (Ford, GM, Chrysler etc.). With their fuel prices, a diesel in the US seems utterly pointless unless you're talking a big diesel V6/V8 4x4 anyway.

Not sure a DPF is anything other than a defeat device as well though.  They only good job they do is giving the car low emissions until the filter needs to regen either passively or manually, then they pump it out the exhaust in 1 go. They store the crap to make the car appear clean then pump it out on a burn.  It still comes out at some point.  IMO the sooner we remove diesels from the road the better, if its not governments or car makers faking it, its MOT stations thrashing a diesel engine before a test to "clear it out".

"post main injection "wash" indirect injection" is this the injection in the inlet to stop the coking up?  If so its still washing and  burning they substance off in the engine and chucking it out the back though surely? I don't think we are anywhere near getting clean but we are certainly trying to fool the public with "Eco" "Green" "blue motion" tech.


http://www.londonair.org.uk/london/asp/news.asp?NewsId=OxfordStHighNO2

[monkeyhanger]

Not sure a DPF is anything other than a defeat device as well though.  They only good job they do is giving the car low emissions until the filter needs to regen either passively or manually, then they pump it out the exhaust in 1 go. They store the crap to make the car appear clean then pump it out on a burn.

Yes and no to the above. The DPF stores soot, but it doesn't chuck it out as is in a discrete glug unchanged rather than spewing it out indiscriminately like you see old pre-DPF diesels doing. It stores it up and combusts it, creating more CO2 and a little water, as the soot will be predominantly unburnt carbon from the hydrocarbons that make up diesel, with a little hydrogenation in there.

When burnt you are left with some incombustible inorganic ash (the build-up of that ash is what gives the DPF its finite life of 120-200k miles before it is filled to the point that the soot storage is not enough) .

In effect the DPF is a CO2 defeat device (storing a bit of carbon in soot form and burning it outside the test cycle), but a bit more CO2 is less harmful than the soot that would otherwise be pumped out. As such it is not a cheat, it converts the soot into CO2, far less harmful.

VW DPFs typically regen at about 45% fill with a capacity of 47g. That's 21.2g to burn on a typical regen. On the assumption that soot is 100% carbon (slightly simplistic, but approx true), 21.2g of carbon generates 84.8g of CO2. My GTD regenned every 600 miles (960km), so that regen is contributing 0.09g per km - wont make a scratch on the CO2 rating.

http://www.myturbodiesel.com/1000q/vw-jetta-tdi-golf-dpf-filter.htm

[mcmaddy]

Jackie, Why don't we just go the whole hog and everyone buy Nissan leafs or Prius ffs. It's ridiculous statements like 'sooner diesels are removed from the roads the better'that cause idiot politicians to think it's a good idea. What do you expect the haulage industry to use to get your groceries to the shop?? Petrol cars pump out more co2s than diesels so should they be removed from the roads too?