petrol or diesel

[syncropaddy]

try driving a G-wagen with the 5 cylinder 3 litre engine.

But a vehicle like that is nothing more than an overweight commercial vehicle and not a car. VW Golfs and Vauxhall Astras from the early eighties were quick enough and certainly not smelly and when the turbo versions came onto the market in the mid eighties then diesel popularity rose with cars like the Audi 80TD and the Passat TD. The UK was miles behind the rest of Europe when it came to diesel cars which is why Mercedes and BMW were slow to introduce turbodiesel models in RHD

 

[dieselman]

The answer to your prayers is coming at last. A big petrol engine giving 31% better economy and it will be in the facelifted C class by about June. This from MB sources: -
"All the petrol engines in the model series have direct injection. One of the highlights is the introduction of the new V6 petrol engine with its innovative and highly efficient BlueDIRECT process in the C 350 BlueEFFICIENCY. The quantum leap in efficiency is particularly well illustrated by the six-cylinder unit: Power has increased considerably, the C 350 BlueEFFICIENCY delivering 225 kW (306 hp) and 370 Nm (previously 215 kW/292 hp and 365 Nm).

Which just goes to show that diesel still reigns supreme for road use due to greater torque output for a wider rev band.

Taking things up a notch, the 6-cylinder E 350 CGI BlueEFFICIENCY uses the same advanced direct injection technology to deliver exhilarating performance as cleanly as possible. The result is a combination of potent acceleration (0 – 62 mph in 6.8 seconds) and CO2 emissions of 201 g/km.


For those who crave more muscular performance, the new 6-cylinder E 350 CDI BlueEFFICIENCY delivers a significant increase in both power and torque to elevate its 0 – 62 mph acceleration to a swift 6.2 seconds. CO2 emissions and fuel consumption have also improved, with the engine delivering from 162 g/km and achieving 45.6 mpg respectively.

Unless we don't consider performance OR economy to be relevant...??

 

[Richard Elliot]

Wrong..! At 247 Lb-ft, that is considerably less than most turbodiesels. Try putting a F1 engine into a full size road car. If you can actually get it off the line the clutch will be toast.


So we are back to comparing a modern high performance petrol to an antiquated low performance diesel AGAIN...which actually emphasizes the original question raised in the first post about diesel advancements.
As I requested previously please compare like to like. For road use you need torque as that gives acceleration force.

Both F1 cars and motorbikes rely on low gearing as a method of torque multiplication, because more torque is required at the driving wheels.

Can you please give the date and source data for the ACE factsheet you cited as the best I can do is find that it's from a school A level factsheet from 1999.
It stated that petrol engines produce zero particulates...Umm

I am not disputing low-gearing, merely your assertion that a high nominal Max Torque figure necessarily implies less gear-changing/higher flexibility. Ask any HGV driver about gear changing...

Forget the F1 car then, and compare a Golf GTi with a TDi. The TDi has undoubtedly higher torque, but unlike the GTi won't pull from 30mph in top, or reach such a high top speed. It would be interesting to see consumption figures for the two, driven identically.

I drive two Merc diesels myself, as you can see, so have no necessity to fly the flag for petrol. However I bought them years ago when diesel was much cheaper than petrol, but that difference has been eroded. In the UK, where diesel is more expensive than petrol, I reckon the financial advantage is lost altogether, and its just personal preference. My other bother is the extreme cost of diesel maintenance, more than petrol since the appearance of CDi ignitions and over-stressed diesel injection systems. Diesels remain 'fashionable' here in Europe, but I expect the tide to turn before too long and diesels to return to their natural habitat, driving generators, ships and tractors under high load at a constant speed.

Afraid I can't find any decent particulate figures, but then again diesel particulate is virtually tautological

 

[Naraic]

I am not disputing low-gearing, merely your assertion that a high nominal Max Torque figure necessarily implies less gear-changing/higher flexibility. Ask any HGV driver about gear changing...

Forget the F1 car then, and compare a Golf GTi with a TDi. The TDi has undoubtedly higher torque, but unlike the GTi won't pull from 30mph in top, or reach such a high top speed. It would be interesting to see consumption figures for the two, driven identically.

I drive two Merc diesels myself, as you can see, so have no necessity to fly the flag for petrol. However I bought them years ago when diesel was much cheaper than petrol, but that difference has been eroded. In the UK, where diesel is more expensive than petrol, I reckon the financial advantage is lost altogether, and its just personal preference. My other bother is the extreme cost of diesel maintenance, more than petrol since the appearance of CDi ignitions and over-stressed diesel injection systems. Diesels remain 'fashionable' here in Europe, but I expect the tide to turn before too long and diesels to return to their natural habitat, driving generators, ships and tractors under high load at a constant speed.

Afraid I can't find any decent particulate figures, but then again diesel particulate is virtually tautological

In other European countries Diesel is cheaper than petrol...so I doubt they will go into decline any time soon.

 

[prwales]

But a vehicle like that is nothing more than an overweight commercial vehicle and not a car. VW Golfs and Vauxhall Astras from the early eighties were quick enough and certainly not smelly and when the turbo versions came onto the market in the mid eighties then diesel popularity rose with cars like the Audi 80TD and the Passat TD. The UK was miles behind the rest of Europe when it came to diesel cars which is why Mercedes and BMW were slow to introduce turbodiesel models in RHD

yes that's true enough about the g-wagen but if you follow any hard driven diesel you are likely to get a face full of black smoke as the driver exeeds its limited power band. So I think they are still smelly or capable of being smelly when driven enthusiastically.

 

[dieselman]

Forget the F1 car then, and compare a Golf GTi with a TDi. The TDi has undoubtedly higher torque, but unlike the GTi won't pull from 30mph in top, or reach such a high top speed. It would be interesting to see consumption figures for the two, driven identically.

You are correct that it won't reach such a high top speed because power is required for top speed, torque for acceleration, hence the old adage still rings true. People buy cars for their published power and then drive the torque.

A TDi will struggle to pull from 30mph in top because it would only be revving at 800rpm, whereas a petrol would be revving at 1500rpm, but driven in a similar fashion the diesel always gives better mpg due to better thermal efficiency.

 

[dieselman]

yes that's true enough about the g-wagen but if you follow any hard driven diesel you are likely to get a face full of black smoke as the driver exeeds its limited power band. So I think they are still smelly or capable of being smelly when driven enthusiastically.

That's an out of date observation, though it is true that direct injection engines produce more smoke due to the lack of ability to mix the fuel and air.
Most of the smoke is the exhaust being cleared of residual soot, after that the engine runs clean.

Obviously, you won't get the smoke for long as you won't stay with a hard driven diesel for long.

 

[dieselman]

I am not disputing low-gearing, merely your assertion that a high nominal Max Torque figure necessarily implies less gear-changing/higher flexibility. Ask any HGV driver about gear changing...

While I'm at it, I'll ask them why there aren't any petrol HGV...

 

[st4]

That's an out of date observation, though it is true that direct injection engines produce more smoke due to the lack of ability to mix the fuel and air.
Most of the smoke is the exhaust being cleared of residual soot, after that the engine runs clean.

Obviously, you won't get the smoke for long as you won't stay with a hard driven diesel for long.

My old man had a old 2.8Td shogun. Part of its charm was the massive puff of black smoke it belched out in the morning.

Its a massive dissappointment the CDi does not do the same.

And it goes, and its faster than the E280 and 350 petrols (3000cc and 3500cc) but I wont expect it to keep up with a 500 as its peak power and high capacity means it makes more or less the same torque, albiet a bit higher in the rev range, but over a wider one due to the higher redline.

A 420cdi might, but MB did not give is that in the UK.

A diesel under load (5 passangers + luggage) will also disguise the mass better than an equivilent size of petrol engine.

 

[Captain Chris]

As far as shipping is concerned diesel is the only way to go not just because of the economy and long life of diesel engines but also for safety. Diesel has a far lower propensity to ignite by spark compared to petrol and when you are measuring fuel capacity in tonnes not liters that makes a big difference to vessel safety!

 

[Alex M Grieve]

As far as shipping is concerned diesel is the only way to go not just because of the economy and long life of diesel engines but also for safety. Diesel has a far lower propensity to ignite by spark compared to petrol and when you are measuring fuel capacity in tonnes not liters that makes a big difference to vessel safety!

Very relevant to road vehicles too Chris. The principal allied main battle tank in WW2 (Sherman, and variants) was nicknamed the "Tommy Cooker". Petrol powered, it had a propensity to ignite when hit, and cook the occupants. German and Russian vehicles did not do so to nearly the same extent.

Sadly, the lessons of WW2 were not learned and the UK light armoured reconnaissance vehicle Scorpion, which was powered by the Jaguar XJ engine and petrol, was still barbecuing it's occupants during the Balkans conflicts of the 1980s! :cry:

 

[prwales]

Very relevant to road vehicles too Chris. The principal allied main battle tank in WW2 (Sherman, and variants) was nicknamed the "Tommy Cooker". Petrol powered, it had a propensity to ignite when hit, and cook the occupants. German and Russian vehicles did not do so to nearly the same extent.

Sadly, the lessons of WW2 were not learned and the UK light armoured reconnaissance vehicle Scorpion, which was powered by the Jaguar XJ engine and petrol, was still barbecuing it's occupants during the Balkans conflicts of the 1980s! :cry:

The Russians used diesel engines in their WW2 tanks, everyone else used petrol, the reason the Sherman gained the nickname of "Ronson" was due to its height and poor armour protection.

 

[Frontstep]

My ships captain (or master) friend as he prefers, looks longingly at nuclear powered American Naval stuff he quotes small amounts of fuel, range power output etc.
Question is can I have a little reactor in my estate then I could run past the petrol diesel argument.

 

[Oarsman]

Question is can I have a little reactor in my estate then I could run past the petrol diesel argument.

I'll let you borrow my little reactor. It's my 8 year old Grandson.

He has more energy than the warp drive on the Starship Enterprise.

 

[Seeker_UK]

The Russians used diesel engines in their WW2 tanks, everyone else used petrol, the reason the Sherman gained the nickname of "Ronson" was due to its height and poor armour protection.

Or to be more accurate, it was called a "Ronson" because 'it lights up every time'.

 

[Seeker_UK]

My ships captain (or master) friend as he prefers, looks longingly at nuclear powered American Naval stuff he quotes small amounts of fuel, range power output etc.
Question is can I have a little reactor in my estate then I could run past the petrol diesel argument.

Ford tried that with the "Nucleon" in 1958. Driving around with controlled nuclear fission going on behind you; wonder why that idea never caught on?

 

[Frontstep]

Well 10 gallons of petrol could get you quite sweaty if set on fire.
I wasn't being too serious about the reactor, I was just wandering if its feasible.

 

[Rappey69]

Well 10 gallons of petrol could get you quite sweaty if set on fire.
I wasn't being too serious about the reactor, I was just wandering if its feasible.

I too often wondered if a vehicle could be powered by its own little reactor.
A great energy source for shipping, very clean but many ports ban any nuclear powered vessels.
Some ports are also banning diesels now because their emissions are too high as they have old technology diesels.
I have a 1.5 morris diesel in my boat, 1965, producing a whole 38hp.
Smokey old thing when cold started but just goes on and on and on ...

 

[Developer]

I have a 1.5 morris diesel in my boat, 1965, producing a whole 38hp.
Smokey old thing when cold started but just goes on and on and on ...

Like the African Queen then.

 

[Alex M Grieve]

Like the African Queen then.

but that film was made in the day when you could use the word "Queen" with impunity! :?