Diesel vs petrol question
 

I drive a courier van, ford transit, manual 6 speed, diesel, 2.2 litre I think. Over a 480km trip, 90% at 100km/h - 60mph, it regularly gets 6.7-7.0 litres per 100km. My car, 3.5litre V6 Camry, petrol, 6 speed auto gets 7.4 litres per 100km on a good trip for the same road at the same speed... over many trips. Van has a far larger frontal area and is fairly brick shaped, has a bull bar too and Im pretty sure its heavier.

Why can the van do better than my car? I understand auto vs manual but there must be more going on, does diesel have far more energy per litre? I drive the van pretty hard but usually I am in no rush in my car.

Yep, diesel has more energy per unit, plus diesel engines have a more efficient combustion process.

Work vehicles are often (maybe usually) geared for steady state cruise. Can handle being fully loaded in terms of overall powertrain performance. But can slow up to speed.

Passenger vehicles are overpowered. Set up for acceleration.

While not strictly accurate, the above makes sense when one tries to use one vehicle in place of the other.

If the diesel is a turbo diesel then it really isn't fair.
You have 2 engines in the diesel versus one in the gas.
That turbocharger is working to recover waste hest in the exhaust to force more air into the engine.
Diesels get better fuel economy with more air.

Yes, they are more economical but they are more harmful to the environment, they are carcinogen when breathing fumes, and they are more expensive to repair but these new cars with this engine.

Gasoline fumes are loaded with benzene which is a major cancer causer.
Is burning more fuel not also harmful to the environment?

If you live anywhere near Autobahn 40 in Germany you'd better think twice before buying a diesel car...

https://www.carscoops.com/2018/11/ge...obahn-network/

Here in Holland more and more cities move towards banning diesels of a certain age, or altogether, in order to meet the micro particulate and NOx air pollution standards.
Recent research has shown micro particulates are far more harmful than was previously assumed, so there's no turning back this trend. Diesel is on its way out, especially in densely populated areas.

Anti-diesel ”reasearch” is pretty well bunk. Politically skewed. Like the faked dangers of second-hand cigarette smoke. False, in that someone’s profit (or power) is what’s really at stake.

The energetic content of diesel makes it indisposable. Non-replaceable. Emissions controls have changed the rest.

The number of vehicles to service urban sprawl is the problem.

Why cities have sprawled is what you aren’t allowed to ask. “Why do we have commuters?” Power and profit are at stake.

Other choices would have precluded what you think of as a dilemma.

.

Oh yeah, it is pretty well bunk.
https://en.wikipedia.org/wiki/Diesel_exhaust
But hey, wikipedia is bunk. Let's roll some more coal.

But then the petrol engine has ignition advance, which the diseasel lacks.

I don't think Europe has adopted the war on NOx style emissions like the US has.

Modern Diesel engines at least in the US can advance the ignition.
But if you have decent fuel there isn't any need to.
Over here advancing diesel injection timing is done for emissions control.

What’s in your water is far worse. Even the best municipal supply. Where’s the outcry.

It’s context. Not content.

Pay attention to a larger picture.

If you believe diesel exhaust gases are safer than even the best tap water you'll have a hard time finding others who share your views.
I think we won't convince each other anytime soon, so its better to stop trying.

Shows you don’t understand even that problem. More serious. Bet you think secondhand cigarette smoke a problem, too.

Few studies can stand up to replication tests. Best you examine your thesis A LOT more carefully.

The problem with the studies is they haven't sufficiently controlled the variables.

Studying miners in a confined space, breathing diesel fumes 10hrs a day isn't a good predictor of the amount of exposure regular folks inhale in day to day living, and what the consequences are.

There's no possible way to put a number of deaths that diesel particulates are responsible for, not to say it isn't happening.

A heart attack triggered by diesel particulate inhalation which results in death doesn't mean the diesel particulates have killed the person; it's entirely likely it's the straw that broke the camel's back, and the person would have succumbed to poor health in the near future.

Again, not saying we should not concern ourselves with the quest for cleaner air, only saying that the issue is too complex to simply say millions of people are dying as a direct result of pollution. How much longer would these people have lived if they had been exposed to 1/4 as much pollution? We'll probably never know.

Remember Europe doesn't have all the emissions stuff we have in the US.

Like what for example?

The sulfur content in the European fuel is a lot higher than than the US.
We use 7ppm sulfur because of the emissions, this started back around 2007.
When did Europe start using their sorry excuse for low sulfur diesel?
We had to start using passive PM soot traps in the mid 90s, most diesels sold in the US had to have very high pressure common rail full electric injector control by 2000 to control NOx and PM, early 2000s egr coolers were needed to reduce NOx, 2007 was the ultra low 7ppm sulfur fuel roll out, then in 2010 active soot trapping using exhaust filters that regen and strict NOx emissions, 2013 or 2014 very strict NOx regulations force use of urea augmented converters on most diesels.

Here it is 10ppm and it is legally called non-sulfur diesel :D

Well this is all new information for me about the american emission equipment, thank you for that.

I don't know when they started reducing sulfur in european diesel, one finnish refinery did it in 1991.
Someone with better knowledge can correct me.

I believe second-hand cigarette smoke is dangerous, plus it's worse than Diesel fumes. But anyway, nobody would be able to convince me that all this anti-Diesel bias is not politically-inclined. Well, many countries could enhance their energy independence retaining old-school Diesels on the road and putting them to run either on pure vegetable oils or biodiesel which could be even made out of residual fats from animal carcasses. I got to learn about Diesel engines due to the influence of Argentinians, Uruguayans and Paraguayans in the '90s, but nowadays it's not so easy to spot so many Diesel cars with Argentinian or Uruguayan plates in the coastal city where I usually go on the summer due to politics on those countries that rendered the Diesel engine too expensive due to left-leaning politicians who embraced the anti-Diesel bandwagon in order to send more money to Venezuela...


Emissions controls and the fuel standards might shift, but I'm also sure the Diesel engine will stay for longer than the sell-outs from the European Parliament are trying to take them out of the road.


I'd also consider the size of certain vehicles as a part of the problem. Sometimes I think Japan was right on classifying vehicles for their size in order to charge lower taxes to smaller ones.

I don't think the research was anti-diesel. Its results were anti-diesel though.
Does that make the research bad?

If research needs to give the results you want to not be bunk, it isn't research anymore.

That's a different matter. Some researches might have their validity even though I'm not satisfied with their results. My objection is toward the left-leaning politicians who pretend to care about the environment and people's health just as an excuse to push their lame agenda. For example, many corrupts who use public funds that should've been destined to the public healthcare system in Brazil pretend to care about people dying supposedly for the effects of Diesel fumes, but their criminal behavior is in fact what denies those people a proper medical care. See?

I value the results of scientific research, where researchers tie their names and reputations to, more than the words of politicians. Even though the latter generally have a more pleasant message (depending on their orientation).

I have nothing with left wing politicians, but 'left wing' research is not a real thing. Nor is 'right wing' research.

I was disappointed because the particulate research I brought up was immediately declared bunk, "research" even. As if I would post it if I thought is wasn't real.
So it is in effect an attack on me too. Guess what, I can do without that.

I'm sure the research is as fair as you can get with funding bias.

Yes left leaning politicians pretend to care about the environment. But their version of caring turns into something that resembles neglect, mismanagement.
It's even hard to tell if their will towards the environment is just ignorance or intentional malevolence.

There is no need to take it personally. In the end, nearly everybody on this board shares a similar goal to reach a good balance of fuel-efficiency (or simply energy-efficiency if we consider the ones who resort to EVs :D) and an eventual decrease on overall emissions.

You know, it is all one big misconception. Emissions research tests all vehicles, not just diesel.
Emissions regulations have let off some aspects of diesel in the past. As diesel engines run lean on light loads by concept, they produce less CO and more NOx than gasoline engines.
Yet emission standards are pushing the levels down:
Fact Check: are diesel cars really more polluting than petrol cars?

The problem here is that many diesel cars cannot actually meet the standards, that's why dieselgate is so widespread. Gasoline cars generally do meet the emissions standards (but not the economics...).
Also the standards do not yet distinguish between micro particulates and larger particulates. Direct injection cars (diesel AND gasoline) produce more micro particulates than carbureted or indirect injection cars; in that aspect the old diesels were less dangerous than the modern 'clean' ones.

But it does contain less benzene: https://www.quora.com/Why-is-benzene...-not-in-diesel

This is a nice neutral description of diesel and its use: https://www.globalsecurity.org/milit...iesel-fuel.htm

and what it does to us:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4894930/

I wouldn't be so sure about it. BTW nowadays that direct injection became more widespread on spark-ignition engines, NOx and even particulate matter turned into a matter of concern on those too. Just to remind, nowadays Volkswagen is resorting to particulate filters even in some vehicles fitted with the 2.0 TSI/TFSI engine.

I wasn't sure, looked it up and altered my post.

My van does highway km so is ok but many cars here - Australia- have problems with the diesel particulate filters that they have to have.

Can anyone explain why diesel has particulates when burnt but petrol does not?

The way I understand it is: it is all about controlling NOx emissions. There are two schools of thought, the first is lots of egr to cool the charge. The problem with lots of egr is lots of soot, so you have to trap it and burn it with the cat and extra fuel. The second is not so much egr which makes more NOx but less soot, then kill the NOx with urea. I know International is having trouble meeting the new standards even with urea. I was told our new Internationals will come with Cummins engines because they can meet smog.

Diesel is a heavier fuel, so it contains longer and more complex hydrocarbon molecules which, if partly burnt, form particles; soot, basically.
Gasoline molecules are smaller; once they break apart the remains are too volatile to create soot and will generally burn up too or form single CO molecules.

Plus what me_and_my_metro said.

NOx effects are pretty well documented

Local research into diesel soot particles resulted in a bit of a surprise:
If a participant had been stuck in traffic, it already showed ...
They end up in your blood and go everywhere your blood takes them ...


Diesel is dead-easy to replace
There's more energy in natural gas by weight
In HGV, up to some 70% diesel can be replaced by CNG - even retrofitted


I burn less CNG than I'd burn diesel

My diesel makes huge 100 to 250 micron particles.
With newer diesels they try to hide the particle matter and you end up with a lot of 1 to 3 micron diesel particles. It just so happens that is also the perfect size for bugs to be packaged in a biological weapon system.
Because when inhaled it goes everywhere throughout the body.
100+ micron is like common dirt and dust, the body's defences filter it out.

Water + alcohol injection, or eventually CNG fumigation, might make more sense. BTW most of the urea used for DEF production is made out of natural gas, so why not to use CNG directly instead? Either as the primary fuel or integrated with Diesel. A trucking company from Brazil has tested an Euro-3 rated Mercedes-Benz Atego with a dual-fuel setup that could operate with up to 95% CNG, and its emissions were comparable to an Euro-5 rated truck even though it didn't have SCR and DPF.

In Texas they are installing cng infrastructure mostly for big rig trucks but anyone can use it.

The first dedicated-CNG coach operating commercially in my hometown since May 2021, with a 320hp, 5-cyl 9.3L Scania engine. It's used for a charter service between Porto Alegre and Charqueadas. This year for the first time both Diesel fuel and CNG became more expensive than regular gasoline in Brazil, but some operators may favor CNG and biomethane over Diesel as there is no need for a complex aftertreatment system.
https://blogger.googleusercontent.co...e%20frente.jpg