BMW 535d: Diesel has come a long, long way...

[Daniel]

You still moderated yourself. You said you thought diesels would take over, and that will not happen as long as people like myself are around.

[ca6]

Yeah, you petrol talibans are hard to exterminate
...but your day will come, mark my words

[idletask]

Originally Posted by Daniel

Now look Josty. The Petrol engine hasnt really gone through a lot of changes. It has only got electronic injection through the past decades. The diesel has been worked oon a lot, because it is a sensible and fuel officiant REPLACEMEANT for people who are not enthustiastic enough to buy a petrol car.

Now look more carefully through the past decade at what petrol engines have gained:

* variable air intake, sometimes continuously so;
* variable intake/exhaust valve timing and/or lift;
* compression ratio increase;
* twin scroll turbocharging;
* Valvetronic;
* direct injection

Diesels? Direct injection has been in truck Diesel engines for decades. The only real innovations are Common Rail (Fiat, Magnetti Marelli), pump nozzles (VW, Bosch) and variable vane turbocharging.

[ca6]

Exactly what you said there about the petrol engines is quite interesting, idletask.
A lot of effort has been put on the petrol engines the last 10-15 years (VTEC and stuff like that), while there hasn't been much progress on the diesels.

I think this tells that the petrol engines are beginning to reach their maximum (agh, I'll probably regret saying that in the future, but ), but there's probably a lot more work to do on the diesels. Just look at BMW and Honda's latest diesels...they're pretty damn good.

I think petrol will still be the choice for conservative supercar makers (read: Ferrari) but makers able to see past the diesel exhaust fumes might find that it has got a lot of potential?

[idletask]

Originally Posted by ca6

I think this tells that the petrol engines are beginning to reach their maximum (agh, I'll probably regret saying that in the future, but )

No they're not. Direct injection is yet to be applied at its full potential. But THE problem is sulfur in fuel.

Thing is, petrol needs to reduce consumption, and the only good way that has been thought of and applied right now is stratified injection. Works great in Japan, it's been working there for more than ten _years_ now, but their fuel is much higher quality than anywhere else in the world.

Stratified injection means you have lean spots in the air/fuel mixture, which generates NOx. NOx traps exist, but sulfur kills them!

And BTW sulfur is also one of the main factors of particulate generating (Diesel soot!).

but there's probably a lot more work to do on the diesels. Just look at BMW and Honda's latest diesels...they're pretty damn good.

Yep there is work, and that goes through homogenizing the air/fuel mixture, which petrol has no need for (that's done in the intake pipe). Problem is, even with the über pressures at which Diesel is injected in the combustion chambers, you have lean air/fuel zones and heavy air/fuel zones. Lean ones generate NOx, heavy ones generate particulates. Hence the more important particulate and NOx emissions of Diesel.

And petrol engines _do_ emit particulates too, but they are way thinner than Diesel ones because of the different chemical composition of these two fuels.

edit: fix typo

[ca6]

Oh...you know a lot more on subject than me

By Japan, do you mean for instance Mitsubishi's GDI engines? I've read that they have kind of a particle emitting problem?

[v0od0o]

I can't believe you guys are having this diesel vs petrol discussion in 2 threads at once

[idletask]

Originally Posted by ca6

Oh...you know a lot more on subject than me

Been gathering info for quite a few years, I love to understand the innards of my boxes on wheels

By Japan, do you mean for instance Mitsubishi's GDI engines? I've read that they have kind of a particle emitting problem?

GDIs are one example, and guess what? Their particle emitting problem is due to sulfur! But they have no such problem in sulfur free (or nearly so) Japan!

As a result, in other countries, GDI engines as well as similarly functioning engines from PSA, VW/Audi, Ford and BMW work with stoechiometric air/fuel mixtures and in fact don't use stratified injection at all. But they will once Japan quality fuel reaches the rest of the world

This same sulfur BTW is the reason why the E320CDI now on sale in the States is only 48 state legal... Had Diesel fuel been the same quality as we have here in Europe, it would be emissions legal even in California

[M5Rangerover]

heheh, my car is a petrol-diesel!

It only revs to 5000RPM and has tons of torque, but no hp, yet it still does 0-60 in 8ish seconds (not bad for only 121hp and 19 years old)

I would probably buy a 535d instead of a 545i cuz you can make them perform better for a lot less. ie: bigger turbos, remapped software, etc. And in daily driving, it is not always necessary to rev to 9000 rpm or whatnot.

PS: anyone ever heard the noise that the x-raid X5 Dakar makes? Its sounds soooooo nice. (3.0 diesel -- 3rd overall in 2004 Dakar, would have come 1st except for a crash.)

[v0od0o]

Originally Posted by M5Rangerover

not bad for only 121hp and 19 years old

is it you or the car that is 19 years old
j/k

[M5Rangerover]

Originally Posted by v0od0o

is it you or the car that is 19 years old
j/k

lol, im only almost 17

[Daniel]

Originally Posted by v0od0o

I can't believe you guys are having this diesel vs petrol discussion in 2 threads at once

I tried my best to move it.

[chaos386]

Originally Posted by M5Rangerover

heheh, my car is a petrol-diesel!

It only revs to 5000RPM and has tons of torque, but no hp, yet it still does 0-60 in 8ish seconds (not bad for only 121hp and 19 years old)

Do you have an '85 325e too?

[M5Rangerover]

Originally Posted by chaos386

Do you have an '85 325e too?

its officially an 86, but it was produced 12/85. Its so close to being an es, the only option missing is the sport seats-- has LSD, sports susp, etc.