Petrol or Diesel

[Laird Scooby]

The thing i've never understood is if diesel is so efficient, why do they need all these thigns hung on the exhaust (ad-blu, DPFs etc) to get them to pass the emissions tests?

Think about that and it stands to reason someone somewhere will come up with a way to cheat the system. Once one manufacturer has done it and got away with it, others will follow.

Just hunted online for the latest Vauxhall scandal and in the side bits, it also cites VAG, Mercedes, Fiat-Chrysler and other results showed the Zafira was known about back in 2015 when Renault owned Vauxhall (or most of it) and supplied the diseasel lumps.

https://www.am-online.com/news/marke...-defeat-device

That really only leaves BMW, Ford and Volvo out of the mainstream manufacturers that haven't been investigated.

When so many manufacturers have been found to have emissions cheating devices installed, can you really believe that diesels are clean? I think not!

[anotheruser]

Originally Posted by Laird Scooby

The thing i've never understood is if diesel is so efficient, why do they need all these thigns hung on the exhaust (ad-blu, DPFs etc) to get them to pass the emissions tests?

I don't think anyone has said they are clean (I assume you mean clean rather than efficient?).
But adding "these things" makes them cleaner compared with an equivalent from the 1970s. It's unlikely a 1970s diesel engine would have space to fit "these things" and even if they did, would the engine know what to do with them? Unlikely.

Fact is motoring IS dirty.
If you think running a diesel from 2020 will produce the same amount of exhaust emissions from the 1970s, please point me to a report clearly stating this. That means a link (or more than one!) from the last 5 years or so, not a reference to a book that only you know about and doesn't appear to exist anymore.

Originally Posted by Laird Scooby

When so many manufacturers have been found to have emissions cheating devices installed, can you really believe that diesels are clean? I think not!

Yes, I believe they produce less / cleaner emissions than those from 40 years ago.
You do not.
Remember. when people say "produce" they don't mean at source in the engine, which is what your argument seems to hinge on. When people say "produce" they mean whatever comes out the back of the car - the exhaust emissions.

Cheating devices no doubt gave them an edge to be able to say how efficient (in terms of emissions) their cars are. Loads of industries cheat and play the system, certainly in Britian. That's what we're best at - trying to find a way around the restrictions.

Go back and read the post/website about the MTU railway engines. Or read about it here
They produce "reduced noise, smoke and exhaust emissions, improved reliability and fuel efficiency." So cleaner and better for the environment than the older 1970s engines.

Nobody is going to accept your view point because you rely on data from the 1970s that only you know about and only YOU say is relevant. Nobody else can judge that for themselves and the way you've presented your lustful argument of making diesel engines sound like the most terrible thing on earth has been the downfall of your credibility. Cheers for your input though.

[BobbyL1970]

I haven't read this entire thread. So if it been covered I apologise.

Many point to diesels being "dirty" which is true to some degree. All fossil fuels are dirty though aren't they??

Due to recent hysteria around just how "dirty" diesels are, there has now been an increase in Co2 emissions, mainly due to people switching back to petrol. It's the first time there has been an increase in many years I believe. So petrol isn't clean by any stretch of the imagination is it??

[dingov70]

Afternoon all , just been reading all the follow up post's . It is all very well reading reports , watching peoples tailpipes & fretting over weird beard news reports .

I based my opinions of factual daily observations using calibrated diagnostic equipment ( I'm an MOT tester ) . I recently tested a 1998 vehicle fitted with what was in essence an Mercedes CDi engine , but fitted with a mechanical injection pump & no fancy devices to cover up what escapes down the exhaust . Passed emission test first rev up .

2016 Jaguar XF treated to "naughty " modification ( DPF knocked out ) failed due to very high smoke readings & visible smoke ! , customer denied & then tried to provide reason for clear evidence of tampering , not falling for that one .

Also from a personal point , I ran my Merc sprinter on veg / bio fuel for many many miles as well as my v70 Tdi both were cleaner with regards to soot in exhaust , I also poked gas analyser probe into tail pipes ( Nova analytical systems ) far lower reading than when using pump diesel .

[tofufi]

Originally Posted by Laird Scooby

The thing i've never understood is if diesel is so efficient, why do they need all these thigns hung on the exhaust (ad-blu, DPFs etc) to get them to pass the emissions tests?

Don't confuse efficiency with cleanliness. My 40 year old Morris Minor can achieve the same fuel efficiency (40MPG) as a new petrol Astra, but the tailpipe emissions of the Astra are much cleaner.

The tailpipe emissions of a DPF equipped car are overall much better than the identical non-DPF car.

Originally Posted by Laird Scooby

Think about that and it stands to reason someone somewhere will come up with a way to cheat the system. Once one manufacturer has done it and got away with it, others will follow.

Just hunted online for the latest Vauxhall scandal and in the side bits, it also cites VAG, Mercedes, Fiat-Chrysler and other results showed the Zafira was known about back in 2015 when Renault owned Vauxhall (or most of it) and supplied the diseasel lumps.

...

When so many manufacturers have been found to have emissions cheating devices installed, can you really believe that diesels are clean? I think not!

As someone very close to what happened with the 'cheat' devices...

The vehicles could run very cleanly. However, in those modes the drive-ability, engine noise/vibration or power wasn't as good. Hence the desire to game the system to improve customer perception of the vehicles when on real world roads.

Since last month, all new cars have to comply with RDE emissions - this means their emissions on a road drive (on a mixture of types of real roads with real traffic) have to lie within a conformity factor of 1.5 of the legislative limit. That's a damn sight cleaner than anything before typically was in real driving

[andy_d]

Originally Posted by anotheruser

Such as the closed mind of diesel = the worst?

The facts are... there are no facts.
Absolutely nobody has done any sort of study taking into account all factors. Perhaps the rise of cleaning products has contributed to people being more ill these days. So much to consider.
But banging on about how bad diesels are isn't going to change someone's mind rather just make you look like an extremist and nobody likes those!



Please provide any scrap of evidence of this because if you can't, people will assume it's a lie and then put everything you've typed into doubt.
If you can't provide any evidence, then best not bother saying something quite "out there"




Let's split the hairs here, yes, you're right.

However the waste products can be made significantly cleaner and thus what comes out the back is quite different.

Take railways.
Old HST engines were fitted with a Valenta (very old) or Paxman VP185 engine. Now all of them currently operating are running with an MTU engine.
Same old diesel going in but completely different smoke coming out.

Somewhere along the way, those waste products have been changed to be not as harmful. Yes, still there to some degree but if you're basically trying to say a 1970s diesel car will provide the same emissions as a 2020 diesel car, nobody will believe you as (while I have no facts to back this up), I bet my next payslip it's not true.
You even said it yourself, a lot is trapped by the DPF or other such filters. If the bas gasses can be changed into soot, that's completely different to it coming out the back of the car.



At the end of the day, no matter what the poor people of the 80s and 90s were told, that was 30/40 years ago.
The young drivers of today care about price, style and electrical gizmos. Perhaps to an extent environmental factors but I suspect both modern petrol and diesels are about the same in the tests by which they are measured for pollutants.

and yet another putting there wallet infront and ahead of peoples health

dont bother to reply , you have joined the Growing list of selfish types on ignore


,,,Bet your also one of the screamers "ohh your not wearing a mask" ,,

[XC90Mk1]

Originally Posted by andy_d

and yet another putting there wallet infront and ahead of peoples health

dont bother to reply , you have joined the Growing list of selfish types on ignore


,,,Bet your also one of the screamers "ohh your not wearing a mask" ,,

But if I used the same research you quote from the 1970s you would discount electric as it’s only suitable for 4mph and 10 mile journeys.

Modern diesels are nothing like they used to be. I know you don’t like to hear it but it’s the inconvineient truth.

[MikeGMT]

Diesel or Petrol! It's all well and good castigating diesel drivers for causing air pollution and especially particulate matter, and EV's will be just as bad or worse. It is often overlooked but if you drive a vehicle of any description you will be contributing to air and particulate pollution by virtue of brake and tyre dust and the dust that has settled onto the ground and then thrown back into the atmosphere by passing vehicles. This can be worse than what is emitted from the exhaust of the latest generation of engines.

I don't think it will be long before the focus shifts to this form of pollution.