One free tank of fuel on 4 ... for free

[Christophe]

You can't generalize like that!

The turbo on diesel improves efficiency!
On a gasoline the turbo especially improves the power and therefore increases consumption!

A turbo diesel engine will consume less than a non-turbo equivalent.

[Matt113]

I thought TD when writing my message, I should have specified it.

[wirbelwind262]

Hello
the role of the turbo is to increase the PME without increasing the specific consumption, it prevents the yield from collapsing outside the maximum torque range.
Good luck !

[Did67]

You can't generalize like that!

The turbo on diesel improves efficiency!
On a gasoline the turbo especially improves the power and therefore increases consumption!

A turbo diesel engine will consume less than a non-turbo equivalent.

It's been a long time since I haven't put a grain of salt

1) Basically, the turbo is a compressor; it is responsible for better filling the cylinders with air (therefore with oxygen)

2) For the same displacement, this increases the power developed by the engine (Diesel or petrol).

3) The compression is accompanied by heating, therefore by an increase in pressure but to the detriment of the quantity of air, the power can be increased by adding an "intercooler".

This is why turbo have abod generalized on large vehicles (Caterpillars, tractors ...): with the same engine, the manufacturer offered 3 powers (the engine with nothing, the engine with turbo, the engine with turbo + intercooler).

4) Having said this, it is not the air that releases power, but the fuel. So obviously, if there is turbo on an engine of X displacement, the injection pump will be adjusted to send more fuel, in principle just enough compared to what it is possible to burn properly with the amount of oxygen contained in the cylinder; so if turbo, for the same cylinder, consumption is increased per engine revolution (compared to the same engine without turbo)

5) The losses of the engine being partly related to its size and to the number / size of the moving parts, it seems logical that if we increase the power of an X engine with the turbo without increasing the losses, the efficiency improves ...

On this principle, I don't think there is a fundamental difference between petrol and Diesel ...

Now, I am not competent enough to know why there is only a little turbo on petrol engines and that this has been generalized on Diesel? Of course, there are all the questions relating to the maximum torque at much lower speed on Diesel, higher compression, less revolutions / minute ... But formally, I don't know.

On the question of starting XUD:

I'm going to scrap a ZX Diesel (not turbo), it must be an XUD I don't know what, but I confirm that it starts like a flower, instantly hot, after a stop even for a few minutes (it turns like a flower, a real treat - 300 km away, and he goes to the scrap yard, the poor man! The bodywork no longer passes technical control).

[Christophe]

Hello
the role of the turbo is to increase the PME without increasing the specific consumption, it prevents the yield from collapsing outside the maximum torque range.
Good luck !

In fact it is the opposite of the EGR right?

So TURBO + EGR = almost atmo?

[Other]

Hello

You can't generalize like that!

The turbo on diesel improves efficiency!
On a gasoline the turbo especially improves the power and therefore increases consumption!

A turbo diesel engine will consume less than a non-turbo equivalent.

The improvement comes from the fact that on a diesel one recovers more energy in the exhaust with a turbo than on a petrol engine
Basically the two engines are similar when it runs at full speed, but at 50% of power the diesel has no throttle therefore maximum filling low injection a lot of diluted exhaust gas for the turbo lower exhaust temperature.
For the petrol engine at mid throttle speed partially closed, reduced filling, despite the turbo, less hot exhaust gas, good ratio whatever the speed.

As said above Did 67 the turbo allows to boost an engine
if the torque decreases with the speed on an atmospheric engine, the filling decreases.
The turbo from an economic point of view is much more interesting on a diesel.

Andre

[Matt113]

it reassures me i was in the right anyway

[Did67]

For the partially closed throttle mid-throttle petrol engine, reduced filling, despite the turbo,
Andre

OK for old "gasoline".

On modern gasoline engines (well a lot, the majority?), There is no longer any carburetor, nor "butterfly"; gasoline is injected into the intake pipes ("multipoint injection") which are always open "fully".

There are quite a few "turbo" gasolines, but they are rare.

I wondered if the absence of turbo on "gasoline" engines was not linked to the risk of self-ignition: if the cylinder is better filled (thanks to the turbo), the pressure at TDC increases, therefore the risk that the mixture ignites before the spark ... The same effect (more air to burn off the fuel) would be obtained by increasing the compression ratio by a few percent ...

Which would be consistent with the fact that the "turbo gasoline" engine I am thinking of (Renault's) is, I believe, a direct gasoline injection engine (in the cylinder) ... oh, all this problematic autoignition no longer arises!

[Did67]

The turbo from an economic point of view is much more interesting on a diesel.

Andre

You mean, I imagine, that Diesel being more complex and beefier by nature, therefore more expensive, the additional cost linked to the turbo becomes negligible?

While on a "gasoline", that would weigh more in the balance?

[Did67]

the SME
In fact it is the opposite of the EGR ...

So TURBO + EGR = almost atmo?

Isn't there a code of good conduct? Speaking "understandable for the boeotians? PMI I know (I had children - Maternal and Child Protection), PME not; EGR ??? Kesako ...

I count myself among the Boeotians. I would like to understand. I don't think I'm completely dumped (see my previous "posts" - it's up to you to judge) ... We criticize the SMS language, put the acronyms, sometimes, to "display" your knowledge and "throw it away", That's not bad either...