Diesel fuel: tankers overcharge their margin

[Did67]

Hello,

I would not want to generate a controversy, but apparently the 2T engine should have had a better future, see this link

http://www.motoservices.com/technique_m ... _temps.htm

Geo;).

I will indeed have to dig into the question.

The article seems to me all the same to make "shortcuts", like comparing the 2-stroke with injection (obviously a huge progress) with the 4-stroke with carburettors ... And insist on the performances - which is not my problem. I don't want to win Le Mans. It is clear that with every second engine stroke, a 2T will rev up much faster and develop more power for the same weight.

I will delve into the question of CO and NOx levels, but by comparing 2T injection with 4T injection. A priori, burning both gasoline, there should be no significant difference (for injection systems dosing the fuel with the same care).

Afterwards, the 2T "burns" more oil and I don't see how that could improve its emission rates. Note that the article evokes the fact that these formidable "2T" do not "smoke almost any more" ... Eloquent.

But these are just my impressions. “Traditionally”, the 2T was much more polluting than the 4T. He has made great progress. But the 4T too! I will try to find emission rates. Not easy. If I find it, I will let you know.

[Did67]

I will indeed have to dig into the question.

It's hard. I can't find any objective figures on the emissions from a scooter per kilometer ...

However, I find two elements strange, which go against the theory of the "Honda conspiracy" (I think it is the 4T engine manufacturer supposed to block any development):

1) This article, where it appears that traditional manufacturers present 4T models in the hope of meeting the standards; here, it is about MBK (which, if I am not mistaken, is none other than Yamaha "for France", or a subsidiary or I do not know what link ...)

View: http://www.mbk.fr/Products/models/booster_x.jsp

2) At Yamaha, this 4T quad is said to be twice less polluting than its 2T equivalent; as far as I know, Yamaha has long been a specialist in 2T (Honda competition opponent); they join 4T by chance now; their engineers may have smoked too many firecrackers?

http://www2.yamaha-motor.fr/actu/spip.php?article1790?

3) This AFP report on the motorcycle show, where it is noted that several manufacturers present 4T models

http://afp.google.com/article/ALeqM5iQ4 ... -BsXSNHm-g

I will continue my research. But I personally have the feeling that the article is a little biased: it compares the most advanced technology (direct injection) on the 2T engine to the classic 4T. The above articles refer to direct injection 4T ...

It should be noted that in the article by Alias, the following passage intrigued me:

Although a few manufacturers, including Kwang Co., Ltd. (With KYMCO brand) and Sanyang Industry Co., Ltd. (SYM) have launched a 50cc four-stroke scooter model to test the market, yet their efforts have been dissuaded by customer complaints because of the relatively low power of such engines (which the engine cannot hide here, ndla).

It implies that faced with the strictest standards in the world in Taiwan (Alias ​​dixit I have not checked), local manufacturers have considered 4T as a solution ... They did not stumble on emissions, but on the lower power.


Explain to me why 2T specialists are looking for a solution with 4T, supposed to be outdated and "imposed" simply by the obtuse minds of Honda engineers ???

If we limit ourselves to 50 cc, there is no photo, the 2T will develop more power than the 4T. I did not find clear evidence on the broadcasts. It is said here and there that the 2T would emit less NOx or CO. Without giving a figure and without specifying whether it is per kw or per km or for the same displacement, and of course for the same technology (direct injection, in this case).

Generally speaking, CO is, it seems to me, from all that I have read, linked to the precision of the dosage of fuel in relation to the air in the cylinder. NOx is rather linked to the combustion temperature. I could be wrong, but I still do not see where is, for the same technology I repeat, the difference on these two points between a 2T and a 4T. On the other hand, in addition to the fuel, the 2T burns oil while on a 4T has the drain.

But as said in a previous post, in 125 cc, the power is not at all my problem. The 125 cc will be more than powerful enough for the use I want to make of it and the purpose I am looking for: reducing the emissions linked to my trip to work (that's where I started).

[Christophe]

https://www.econologie.com/les-moteurs-2 ... s-717.html

[Did67]

This is precisely the article I'm talking about. Someone already told me.

And that leaves me with a very very mixed feeling to say the least (I have become very careful in my formulations, you know).

Without triggering another pugilat, I think I can say that it absolutely does not convince me. But let me make it clear once again: I am for total freedom of expression.

See my observations above: roughly speaking, faced with stricter standards and consumer demand for less polluting products, why would 2T specialists rip towards 4T if 2T was the best of the best? The "Honda plot" seems a little fair to me ... They still have some fierce competitors who would be sure to field them if they were completely out of the game (from a technological point of view).

The bias underlying the article, everyone can see: there is a regulation that limits scooters authorized to minors to 50 cc (and not to a power of x kW! Which is silly in itself!) . Hence a particular market. On that, impossible to reach the same power with a 4T. And young people love power. So dominance of 2T on this segment. And problems already with the previous standards (Euro2) with the 2T. Result: a search for a solution, found with direct injection. So for a while, a technological advance in 2T. This is where the article by Alias ​​is located ... Today the 4T has also started direct pilot injection (which was not necessary to reach the Euro 3 standard) and - it seems - took over. History of returning to Euro4 standards, it seems to me (see cited articles) that more and more manufacturers of 2T switch to 4T. On the 125 cc and even on the 50 cc. I don't think they do it for fun, for fashion or to please Honda ...

I am not a specialist. But that's the conclusion I come to today. I keep looking for more tangible data (emission figures per kilometer) - I can't find any. I will try the German or English speaking sites.

[geotrouvetout]

Hi Did67,

I don't know if you read following the article on the link at the bottom of the page which leads here:

http://www.motoservices.com/technique_m ... -Alias.htm

maybe an answer ???

Geo;).

[Did67]

Hi Did67,

I don't know if you read following the article on the link at the bottom of the page which leads here:

http://www.motoservices.com/technique_m ... -Alias.htm

maybe an answer ???

Geo;).

Yes Yes...

But as the Alias ​​article does not convince me, because a little too much "the white knight who all alone attacks the nasty lobby of 4T" ... with some ambiguities that I have already underlined, I am looking for other sources. But, being a little incredulous and suspicious, I do not demonstrate anything !!!

I have searched on German-speaking sites:

- Evinrude has posted data showing that their E-TECH is in line with European standards (Euro3, I believe); the system is a considerable step forward (like all direct injection systems) for the 2 T engine

- I also found other elements, less favorable ...

- what I would like is to compare the '"nec plus ultra" of the 4T (in particular the 4T engines with direct petrol injection), with the "nec plus ultra" of the 2T; otherwise the comparison does not make sense

- it seems that the 2T engine has an advantage over the 4T (I did not take notes - I do not remember if it is for NOx or CO); but there are also indications on the emissions of higher carcinogenic benzene cyclic derivatives, etc ...

- finally, I had found an article which indicates that the same engine goes from a 'homogeneous' operation (the air-gasoline mixture has the same concentration almost everywhere in the cylinder) to 'stratified' (there is a richer area around the spark plug and more paved elsewhere) depending on the engine speed; however, it is the stratified regime, with direct injection, which allows the feats of emission reduction (we create a rich area around the spark plug , which ignites and sets fire to the too poor area that would not ignite on its own) ...

I am pleased to note that 2T, with direct injection, separate lubrication and stratified combustion, is now reaching very low levels of pollution, which I never imagined! It is a question of drastically reducing the oil consumption with cylinders having a ceramic treatment (that said, it is technology of formula 1, must see to the use)

Now, I also note that, in the perspective of Euro4 standards, 2T specialists are introducing 4T in their range !!

So, I conclude that severe names are useful. That it is better to learn than to judge on commonplaces. But I still do not have a general table giving the majority of emissions reduced to kWh or standard km.

[geotrouvetout]

Hi Did67,

I see that you go far in your analysis and your research, it's all to your credit, we can also deduce for the 2T a gain in the production of the engine as well as the weight (because need of a lower displacement) this which is not negligible.
For use in hybrids as well as "small" vehicles the weight gain also allows serious savings.
Also, fewer moving parts should reduce mechanical losses, and increase the yield.
By comparison (if the figures announced prove it) the 2T still has the advantage energetically speaking (design, manufacture-production, weight, maintenance, pollution etc ....).

Geo;).

[Woodcutter]

Well here it is: with cheap diesel and new efficient and low-consumption engines, they have drawn 80% of French motorists into the trap (absolute world record I think) [...]

No.
Belgium and Luxembourg do better than France (78.2) with respectively 79.5 and 80% ...

Note that Spain, Norway and Portugal are not far behind.

[Christophe]

FYI, there is currently around 20 cents difference in Belgium between petrol (1.6) and diesel (1.4).

[Woodcutter]

[...] NOx is rather linked to the combustion temperature. I could be wrong, but I still do not see where is, for the same technology I repeat, the difference on these two points between a 2T and a 4T. [...]

On a 2T, combustion takes place at a lower temperature, or at least, the T ° reached at the end of combustion is lower.

Just to crop it a bit, it seems to me that these items touting the 2T are starting to date a bit, and it makes me laugh about the attacks on Honda when you know that they are the ones who pushed the most far research on 2T, with ARC technology (not on the 50 cm3, that said).

Finally, mention is made of the Euro 4 standards, but I do not believe that the 2T can manage to pass them, even if it is true that for a 50 cm3, the 2T technology, lighter and cheaper (though?) Remains a good solution.

With regard to polluting emissions, the ADEME recently released studies of 2 wheels, but not less than 50 cm3 (or so I have not seen ...)