Large Diesel cycle engines have 55% efficiency, the highest conversion of fuel into power by any internal or external combustion engine.
Truck, bus and latest car diesels have peak of 45% (and soon 50%) - lower in driving conditions of course, but still at least 20% higher from petrol engines. How they are much more efficient at low power / idling (when the proportion of fuel used per energy produced remains nearly constant for diesel, but not for petrol) helps too... Or how efficiency of the cycle is not limited by detonation of fuel mixture, but simple strength of engines components (and higher compression ratio, temperature of combustion, expansion ratio)
Which still doesn't change how a typical small diesel being put in cars has around 20% higher energy conversion efficiency (density of energy in the fuel doesn't isn't even part of the equation)
And when going into larger engines... really large diesels have highest conversion of fuel into power by any internal or external combustion engine, over 50%.
Horsepower isn't everything, especially since, in the case of this "battle", what looks like "weak" diesel tends to give high torque - a much more useful thing in many driving circumstances.
But even that is a poor metric - distance travelled or energy conversion efficiency are much better.
It is for fuel efficiency, also. Large Diesel cycle engines can go above 50% (really large, used in ships have 55% efficiency, highest conversion of fuel into power by any internal or external combustion engine), that's something the Otto cycle engines can't get anywhere near to.
While it's not so great when the engine size gets smaller, it's still much better - engines in trucks and buses, and also latest car diesels, have peak of 45%, should also hit over 50% in near future (average efficiency under driving conditions is lower of course - say, 35% - but in a diesel car still over 20% better from best petrol engines) - and it improved more than 10% over the last 2 decades.
And still has room - Diesel cycle is not limited by properties of fuel-air mixture in the same way as Otto cycle is (knock); has higher efficiency thanks to higher compression ratios - limited only by strength of its components, not detonation of fuel mixture; also higher temperature of combustion and greater expansion ratio allowing to extract more energy.
Those things mean that engines must be tougher (so typical usage is actually low stress one) and heavier; more reasons why they are more popular in trucks.
Early high torque is also related to how diesel engines are much more efficient when at low speed, low power (or outright idling) - for any partial load, the proportion of fuel burned per energy produced remains nearly constant (not the case for petrol engine)
PS. And power in consumer cars seems to be not really a case of "need", but how people perceive "number next to HP = better" - while torque is also crucial. In many driving situations "weak" diesels have much better acceleration... (and not a case of last decade improvements - VW SDI engines, "really weak" when it comes to HP, are actually somewhat more snappy at lower speeds than similar turbodiesels)
Downside of a diesel is that they need a turbocharger and intercooler to operate.
Huh? What are you talking about?
Sure, those parts are pushed for small cars because of perceived need for larger number next to HP, but they aren't actually needed. A VW SDI car ends up snappy enough (actually better from TDI at low engine speeds), typically with higher mpg; and reliability is a nice bonus.
I know in which one I would prefer to be... but I prefer for the energy to crush as much as possible parts of the car away from the occupants, not the occupants (which does give false impression in small crashes (doesn't EN have separate word for this? Mine language has, quite distinct and handy...); false perceptions of safety tend to decrease it BTW)
Also look up very old crash tests, look how pathetic they are.
On the other hand, it also weighs twice as much as the MG and handles like it, so good luck avoiding an accident that he could.
Handling might not necessarily follow greater weight like that - a lot of old cars had quite horrible one; suspensions/brakes/etc. greatly improved over the decades, plus now some electronic aid might help you out.
What? Zero gain only when it comes to ethanol (but with all the negative consequences of mass agriculture, resources for auxiliary equipment, etc.) would be beneficial?
A lot more than beyond-basic would be required for this, probably (but by basic I meant mostly things which aren't really needed, but we do it anyway for, say, perceived comfort - for example two showers daily are pleasant...and that's it)
In my book - if it's too cold for normal warm gloves with two tips slightly exposed, it's too cold for any normal ones (thin enough to allow reasonable touchscreen handling in the first place)
"Scathing commentary" probably goes too far... OK, real reason to answer: pointing out how your username can be quite easily misread, in my language, as a word for "hell";p
(though mentioning History Channel as the source makes me both sad (because of the horrible gimmicky "whoa!" visual style of many US and partly UK documentaries nowadays - luckily Planete seems to resist, so far) and suspect (I recently witnessed describing some trijet with aft-mounted engines as "737")
Slashdot Mirror
Well...
http://video.google.com/videoplay?docid=-8517523543573905150
(not only SymbOS, also Contiki)
Large Diesel cycle engines have 55% efficiency, the highest conversion of fuel into power by any internal or external combustion engine.
Truck, bus and latest car diesels have peak of 45% (and soon 50%) - lower in driving conditions of course, but still at least 20% higher from petrol engines. How they are much more efficient at low power / idling (when the proportion of fuel used per energy produced remains nearly constant for diesel, but not for petrol) helps too... Or how efficiency of the cycle is not limited by detonation of fuel mixture, but simple strength of engines components (and higher compression ratio, temperature of combustion, expansion ratio)
Which still doesn't change how a typical small diesel being put in cars has around 20% higher energy conversion efficiency (density of energy in the fuel doesn't isn't even part of the equation)
And when going into larger engines... really large diesels have highest conversion of fuel into power by any internal or external combustion engine, over 50%.
Horsepower isn't everything, especially since, in the case of this "battle", what looks like "weak" diesel tends to give high torque - a much more useful thing in many driving circumstances.
But even that is a poor metric - distance travelled or energy conversion efficiency are much better.
It is for fuel efficiency, also. Large Diesel cycle engines can go above 50% (really large, used in ships have 55% efficiency, highest conversion of fuel into power by any internal or external combustion engine), that's something the Otto cycle engines can't get anywhere near to.
While it's not so great when the engine size gets smaller, it's still much better - engines in trucks and buses, and also latest car diesels, have peak of 45%, should also hit over 50% in near future (average efficiency under driving conditions is lower of course - say, 35% - but in a diesel car still over 20% better from best petrol engines) - and it improved more than 10% over the last 2 decades.
And still has room - Diesel cycle is not limited by properties of fuel-air mixture in the same way as Otto cycle is (knock); has higher efficiency thanks to higher compression ratios - limited only by strength of its components, not detonation of fuel mixture; also higher temperature of combustion and greater expansion ratio allowing to extract more energy.
Those things mean that engines must be tougher (so typical usage is actually low stress one) and heavier; more reasons why they are more popular in trucks.
Early high torque is also related to how diesel engines are much more efficient when at low speed, low power (or outright idling) - for any partial load, the proportion of fuel burned per energy produced remains nearly constant (not the case for petrol engine)
PS. And power in consumer cars seems to be not really a case of "need", but how people perceive "number next to HP = better" - while torque is also crucial. In many driving situations "weak" diesels have much better acceleration... (and not a case of last decade improvements - VW SDI engines, "really weak" when it comes to HP, are actually somewhat more snappy at lower speeds than similar turbodiesels)
Downside of a diesel is that they need a turbocharger and intercooler to operate.
Huh? What are you talking about?
Sure, those parts are pushed for small cars because of perceived need for larger number next to HP, but they aren't actually needed. A VW SDI car ends up snappy enough (actually better from TDI at low engine speeds), typically with higher mpg; and reliability is a nice bonus.
None are drive-by-wire now afaik, but electronic controls which function incorrectly could still present a major problem.
As a side note, down a mountain road I want engine breaking...
And what if those ABS, stability programs and traction control function incorrectly?
Would be so great if more people would do it...
XP had thermal diode to quickly shut it down in such case. Which might be even more fitting?
Chassis of Land Rover Discovery vs. monocoque of Renault Espace
I know in which one I would prefer to be... but I prefer for the energy to crush as much as possible parts of the car away from the occupants, not the occupants (which does give false impression in small crashes (doesn't EN have separate word for this? Mine language has, quite distinct and handy...); false perceptions of safety tend to decrease it BTW)
Also look up very old crash tests, look how pathetic they are.
Think of all the false positives if you drop your ear necklace.
Hm, just how big of a chance of extra freak-out for TSA people there is, if most male passengers implied they enjoy it? ;p
Which population?
Sheep? I take it you don't utilize any thermostats in the heating of your house? Shun automatic transmission?
For that matter, why not remember and write in IP in the browser bar?
whoosh
Who and why settled on such round number?
What for?
On the other hand, it also weighs twice as much as the MG and handles like it, so good luck avoiding an accident that he could.
Handling might not necessarily follow greater weight like that - a lot of old cars had quite horrible one; suspensions/brakes/etc. greatly improved over the decades, plus now some electronic aid might help you out.
What? Zero gain only when it comes to ethanol (but with all the negative consequences of mass agriculture, resources for auxiliary equipment, etc.) would be beneficial?
A lot more than beyond-basic would be required for this, probably (but by basic I meant mostly things which aren't really needed, but we do it anyway for, say, perceived comfort - for example two showers daily are pleasant...and that's it)
In my book - if it's too cold for normal warm gloves with two tips slightly exposed, it's too cold for any normal ones (thin enough to allow reasonable touchscreen handling in the first place)
"Scathing commentary" probably goes too far... OK, real reason to answer: pointing out how your username can be quite easily misread, in my language, as a word for "hell" ;p
(though mentioning History Channel as the source makes me both sad (because of the horrible gimmicky "whoa!" visual style of many US and partly UK documentaries nowadays - luckily Planete seems to resist, so far) and suspect (I recently witnessed describing some trijet with aft-mounted engines as "737")
Is freaking out / affecting people like that about 616 any better?...
Wait and see and mimic, also be exposed - might help with not getting old too fast.