Clive wrote in message ...
Or perhaps you can't argue any of my points so you resort to insults?
Modern diesels have much higher injection pressures which leads to
better atomisation of fuel leading to lower particulates and better mpg.
Further the newer systems have injection through a phase of five
injections during the burning phase cutting down on the "Diesel knock"

It may well have cut it down but even the most refined diesel engine today to
me sounds like a petrol engine from 30 years ago.

improve by using direct injection now. However because of the speed of
burn petrol engines need to be run at high revs to get any torque from
them where as a diesel has (because of a better controlled burn) much
greater torque throughout it's rev range. Another point to mention, is

Given the limitation of a diesels rev range thats not saying a lot. Plus
a lot of the torque comes from the greater mass of the flywheel in a
diesel, required for the high compression and inherent lumpiness rather
than the magical properties of the burn. And lets not forget that most diesels
these days have a turbo to get any reasonable performance out of them. A better
like for like comparison would be a turbo diesel against a turbo petrol in
which case the diesel may as well give up and go home.

the continual ideal that diesels are dirty. All fossil fuel engines
are dirty, whether steam (coal) diesel or petrol. A lot used to be
made of the soot from buses due to (normally) incorrect injectors
settings or temporary over fuelling whilst waiting for the turbo to spin

That may be the case , but it happens an awful lot. I can't remember the
last time I saw a brand new petrol car blowing out black smoke from its
exhaust but I've seen a number of new diesel cars doing when under high load.
They can't ALL be lemons.

up. It's now recognised that in fact greater danger comes from PM10s,
very small particulates which can't be seen with the naked eye. These
are increasing in modern diesels so most are now fitted with particulate
traps, but petrol engines have always produced them and so are accepted.

They don't produce them to the same extent and its only been the rise of
diesel use that has prompted questions being asked about them.

One last point, my diesel has a cat.

I stand corrected on that. However , lets be honest , a diesel engine is
really stone age technology. The only thing it has going for it is fuel
efficiency , thats it. If petrol engines ever match diesel in that the diesel
engine will vanish as quick as manufacturers can flog off their old models.

B2003

I stand corrected on that. However , lets be honest , a diesel engine is
really stone age technology.

Or perhaps the shape of things to come as petrol moves to direct injection?
Petrol engines are cheap to make which is why they are used in cars.
Everything else uses diesel.

The only thing it has going for it is fuel
efficiency , thats it.

That is a pretty big "it" and more than reason enough for me to buy diesel.

If petrol engines ever match diesel in that the diesel
engine will vanish as quick as manufacturers can flog off their old models.

But the reverse is happening. Private cars, which were a true bastion of the
petrol engine, are rapidly moving over to diesel. Petrol engines are unlikely
to ever match diesel engines for efficiency unless some magical way is
found to increase the compression ratio without pre-ignition. That is
basic thermodynamics stuff. Of course using direct injection you could raise
the compression because the fuel need not be there until you want it to
go bang. So raise the compression of your petrol engine a fair bit and inject
the fuel at the right time. No need for a spark any more... and you have
a diesel engine

Logical development!

David

--
****** David Round - EMail Tel (01248) 382416 *****
*****These are my own views, I represent nobody (Well maybe myself)*****
***********I guarantee nothing - Particularly the spelling**************

In message , Boltar
writes
However , lets be honest , a diesel engine is really stone age
technology. The only thing it has going for it is fuel efficiency ,
thats it. If petrol engines ever match diesel in that the diesel engine
will vanish as quick as manufacturers can flog off their old models.
Look at it another way, only cars use petrol engines, all other forms of
energy needs are met by diesel. Some cars, all trains, all buses, all
lorries, all modern ships. Now if the technology is so stone age,
what's it's great pull and why aren't petrol engines used instead?
--
Clive

In message , D.P.Round
writes
Of course using direct injection you could raise the compression
because the fuel need not be there until you want it to go bang. So
raise the compression of your petrol engine a fair bit and inject the
fuel at the right time. No need for a spark any more... and you have a
diesel engine
Sorry, that's already been tried. NATO wanted a fleet of tanks to run
on any fuel but it turned out that as the fuel got thinner the mpg went
down very quickly and it was found that using petrol in this way diluted
lubricating oil on the cylinder walls leading to higher ware rates.
Further remember direct injection of petrol in cars has been around
since the 1950s, plenty of time for development, but very little done.
--
Clive

"D.P.Round" wrote in message
...

If petrol engines ever match diesel in that the diesel
engine will vanish as quick as manufacturers can flog off their old models.

But the reverse is happening. Private cars, which were a true bastion of the
petrol engine, are rapidly moving over to diesel. Petrol engines are unlikely
to ever match diesel engines for efficiency unless some magical way is
found to increase the compression ratio without pre-ignition.

Turbo petrol engines match turbo diesel engines for efficiency
(although only Audi seem to produce comparable models).
Drivers of petrol engines just don't think it is worth paying
1000 pounds for a turbo in an ordinary car. Anyone doing
enough miles to save money will also want the cheaper fuel.

On 6 Apr 2004 01:30:25 -0700, (Boltar) wrote:



It may well have cut it down but even the most refined diesel engine today to
me sounds like a petrol engine from 30 years ago.


Thats because you're an idiot. Who cares what you think.

As a matter of fact I would enjoy watching you fulminate impotently in the
rear view mirror as you inhale a draught of my delightfully aromatic PM10s.

If oil burners are good enough for BMW and Daimler Benz customers *and* EU
emmission regulations, they are good enough for the rest of us.


greg

--
"vying with Platt for the largest gap
between capability and self perception"

Clive wrote:
In message , Nick Finnigan
writes


Is it more expensive to produce, relative to petrol?


A hard question to answer, but any differences are small relative to
the changes in duty.

I remember one of the fuel companies using the excuse that diesel and
home heating oil were the same fraction, leading to elevated prices in
the winter months.

In NZ diesel is still just over 50% of petrol price, 67 cents / litre
against $1.20 for 96 octane unleaded (= £0.25p and £0.40p respectively),
with the difference largely due to excise. Diesel users however have to
pay a road user charge which varies with tare of vehicle - about 5 cents
per kilometre for a 3 tonne Isuzu 4WD. Still works out a lot better
than petrol.

Martin, auckland

In message , Greg Hennessy
writes

It may well have cut it down but even the most refined diesel engine today to
me sounds like a petrol engine from 30 years ago.

This won't concern you as your petrol vehicle never fails, but two years
ago I was stranded in France with a diesel Almera using the old fuel
pump. The car failed electrically, everything stopped including the
speedometer, but I was still able to drive 200 miles because the engine
was not dependant on any electrical power. Oh and by the way, most car
failures are electrical.
--
Clive

Greg Hennessy wrote in message . ..
On 6 Apr 2004 01:30:25 -0700, (Boltar) wrote:



It may well have cut it down but even the most refined diesel engine today to
me sounds like a petrol engine from 30 years ago.


Thats because you're an idiot. Who cares what you think.

Well apparently you since you bothered to reply and go so irritated. Calm
down mate, keep your flat cap on.


As a matter of fact I would enjoy watching you fulminate impotently in the
rear view mirror as you inhale a draught of my delightfully aromatic PM10s.

Would that be because I'm stuck in a half mile queue behind you as struggle
top maintain the speed limit going up a hill in your asthmatic diesel?


If oil burners are good enough for BMW and Daimler Benz customers *and* EU
emmission regulations, they are good enough for the rest of us.

BWM and Daimler make them because people want them. People want them because
of the cost of fuel. In the US where petrol is the price of water do you see
many diesel cars? No. Now if they're so wonderful why are there so few in
such a car loving nation?

B2003

In message , Boltar
writes

BWM and Daimler make them because people want them. People want them
because of the cost of fuel. In the US where petrol is the price of
water do you see many diesel cars? No. Now if they're so wonderful why
are there so few in such a car loving nation?
Will, you are uninformed aren't you. Continental America see
temperature extremes which mean diesel fuel can solidify at the low
temperatures they experience. Such a high brow argument is obviously
well beyond what you can comprehend , so stop there before you look even
more ignorant, that's a good lad.
--
Clive