BBC Article on real world emissions testing

lordrobs · 17 Oct 2017 at 12:59

http://www.bbc.co.uk/news/resources/idt-sh/how_toxic_is_your_car_exhaust

Skip to the results if you don't want the guys life story but in short they tested a mk3 petrol Golf with 160k on the clock against a Euro 4 Octavia 1.9 diesel to see how they stacked up in terms of real world emissions.

The Octavia beating the Golf by some margin in all areas- no real surprise there. They then went on to compare the results to real world emissions of current models and state that a current 1.6 CVT Qashquai pumps out 18 times the NOX of the old 2009 PD TDI!

In contrast they state two examples of current models that do meet the current regulations with real world testing.

What are your thoughts? I knew that current vehicles were never going to stack up well with real world measured figures but can they really be that much worse than what I presume is an old PD TDI?! I also find it amazing that there are cars out there that currently can meet the regulations under real world driving.

VincentHanna · 17 Oct 2017 at 13:18

Yeah I read it earlier and it was quite interesting (albeit it went on a bit)

Crazy that the Qashquai is the best selling car in the UK and pollutes that badly in real World conditions.

Good on Mercedes for making the c250 comply with the actual regulations as well!

paradigm · 17 Oct 2017 at 13:30

VincentHanna said:
Good on Mercedes for making the c250 comply with the actual regulations as well!

More to the point, the VW Tiguan does comply also.

Seems that far more than VW needed to be chastised for the emissions "scandal"

VaderDSL · 17 Oct 2017 at 13:36

Are the cars that meet the actual nox emissions using SCR (Ad Blue?)

What are the drawbacks with Ad Blue (from tech point of view?) is it a vastly more complex system? Granted you need to re fill it every now and again, but does it damage engines? does it reduce fuel consumption? Or will it get to the point that every diesel will have to use an SCR to reduce nox?

Dangerous Dave · 17 Oct 2017 at 13:38

It was an interesting article, it didn't go into detail on the new Tiguan and C250 that can match or beat EU6 figures in real world driving. I suspect this is due to both these cars using Adblue where the EU6 Qashquai doesn't which is ironically where the diesel debate started with VAG not using the system in the states.

I suspect a lot of current EU6 diesel cars without Adblue systems are likely to be poor in real world driving, what will be interesting is the new MOT test that is coming in what figures are going to be used to confirm the emissions system is in place and working correctly if they use figures near the EU6 limit it could end up with EU6 cars with fully working systems failing the test.

Dangerous Dave · 17 Oct 2017 at 13:46

VaderDSL said:
Are the cars that meet the actual nox emissions using SCR (Ad Blue?)

What are the drawbacks with Ad Blue (from tech point of view?) is it a vastly more complex system? Granted you need to re fill it every now and again, but does it damage engines? does it reduce fuel consumption? Or will it get to the point that every diesel will have to use an SCR to reduce nox?

Adblue is a pain it's a secondary tank that needs filled up, depending on mileage/tank size/model this can be every 1000-1500 miles as with mpg manufactures quote figures on tank fulls that are not realistic. Once empty the car won't start up, you do get plenty of warning but I expect plenty of drivers will ignore this.

Kiethton · 17 Oct 2017 at 13:50

Dangerous Dave said:
Adblue is a pain it's a secondary tank that needs filled up, depending on mileage/tank size/model this can be every 1000-1500 miles as with mpg manufactures quote figures on tank fulls that are not realistic. Once empty the car won't start up, you do get plenty of warning but I expect plenty of drivers will ignore this.

Sure that could be mapped out easily enough, especially if the owner was remapping the car for other reasons (power/efficiency/limiter) anyway

thewanted · 17 Oct 2017 at 13:50

Dangerous Dave said:
depending on mileage/tank size/model this can be every 1000-1500 miles

Do you have specific examples of this? I did 13000 miles before I got the "fill up with Adblue in the next 1200 miles" warning, and my car has a 24L AdBlue tank. Hardly massively inconvenient.

Dangerous Dave · 17 Oct 2017 at 14:01

thewanted said:
Do you have specific examples of this? I did 13000 miles before I got the "fill up with Adblue in the next 1200 miles" warning, and my car has a 24L AdBlue tank. Hardly massively inconvenient.

I've use a Ford Ranger for towing, lucky to get 2k with no/little towing I have had sub 1k on a tank towing at capacity. Brother in law has a 3L TDI A6 he drives mainly around town and doesn't hang about with a sub 30 mpg average, I am not sure on the tank size but it doesn't have the bigger one he rarely gets more than 2-3k on a tank dealer says working as designed.

thewanted · 17 Oct 2017 at 14:06

Dangerous Dave said:
I've use a Ford Ranger for towing, lucky to get 2k with no/little towing I have had sub 1k on a tank towing at capacity. Brother in law has a 3L TDI A6 he drives mainly around town and doesn't hang about with a sub 30 mpg average, I am not sure on the tank size but it doesn't have the bigger one he rarely gets more than 2-3k on a tank dealer says working as designed.

I don't know which Ranger you drove, but this article says that at least one of them has a 20L AdBlue tank. If you're burning through all of that in <1000 miles, that's rather worrying.

Dangerous Dave · 17 Oct 2017 at 14:10

thewanted said:
I don't know which Ranger you drove, but this article says that at least one of them has a 20L AdBlue tank. If you're burning through all of that in <1000 miles, that's rather worrying.

That's towing so the engine is under heavy load. It's under these loads where significant amounts of Adblue are needed to keep the emissions under control. Drive an Adblue equipped car hard or on short trips and it is going to use significant amounts.

I am sure I have read an article where VAG knocked back Adblue usage on the 3L models when under heavy load to reduce usage. They released an update after diesel gate to stop this and the usage went through the roof. I will find out as plan on getting a 3L TDI Amorak

Nasher · 17 Oct 2017 at 14:14

The emissions testing needs to change, it's pretty silly. Everyone is moving to small turbo engines, but they are actually worse in the real world than bigger NA engines when you look at more than just Co2.

thewanted · 17 Oct 2017 at 14:16

Dangerous Dave said:
That's towing so the engine is under heavy load. It's under these loads where significant amounts of Adblue are needed to keep the emissions under control. Drive an Adblue equipped car hard or on short trips and it is going to use significant amounts.

I am sure I have read an article where VAG knocked back Adblue usage on the 3L models when under heavy load to reduce usage. They released an update after diesel gate to stop this and the usage went through the roof.

I'm aware that the consumption is relative to the amount of fuel used

I'm not arguing since you have real world experience and I have no idea what you're towing, however these caravanners seem to get much better consumption than you, although most of them don't state which vehicles they have which is annoying.

GravyMonster · 17 Oct 2017 at 14:23

Dangerous Dave said:
Adblue is a pain it's a secondary tank that needs filled up, depending on mileage/tank size/model this can be every 1000-1500 miles as with mpg manufactures quote figures on tank fulls that are not realistic.

My C250d is still on its first tankful of AdBlue and I'm just about to hit 10k miles. IIRC I've still got about 1/3 of the tank left.

1000-1500 miles is way off the mark, for Mercedes at least.

Bear · 17 Oct 2017 at 14:23

Wonder if the report was sponsored by VAG? Let's test two VAG cars and say the newer one is much better than it really needs to be and the brand new ones are even better. Could have come straight out of VAGs marketing department.

vanpeebles · 17 Oct 2017 at 14:39

Yeah I thought that, is also failed the mention the effects of scrapping a car and getting another one, rather than just keeping the original going.

VincentHanna · 17 Oct 2017 at 14:45

Bear said:
Wonder if the report was sponsored by VAG? Let's test two VAG cars and say the newer one is much better than it really needs to be and the brand new ones are even better. Could have come straight out of VAGs marketing department.

It's the BBC, of course it wasn't.

Bear · 17 Oct 2017 at 14:49

VincentHanna said:
It's the BBC, of course it wasn't.

It may be on the BBC website but the bloke that wrote it is a freelance journalist.

lordrobs · 17 Oct 2017 at 16:06

I think the biggest point for me was the worse emissions on a modern CR diesel compared to an old PD TDI though. That said of the three cars highlighted, two of them run Renault dci lumps. It would also be interesting to know what the comparable manual 1.5 dci Qashquai manages.

A very good point on the modern petrols though. After years of downsizing and adding FI how will it shake things up if those 1.0 Ecoboost or TSI engines start appearing hugely more polluting than their 1.6 NA predecessors? I know it is hugely unscientific but those Fiat Twin Air 0.9 engines for example, have you noticed just how much black crud is around the tailpipe on most of those :eek:

Nasher · 17 Oct 2017 at 16:50

If the tax brackets reflected real world emissions the whole thing would be turned on it's head. With diesels dominating the top making V8s look clean

There was a site that did it, I can't remember which. But it was funny seeing cars like the 370z beating low powered TDIs for air quality.