Automotive Perfection

[nota]

.....and I don't get excited when nearing the read line in a petrol car. It is just a lot of noise and no better performance.

Not if you're in the 'right' car, with a hot cam (IME)

That 'rush to redline' can be pretty addictive....

(Coming to think of it, a low end torquey diesel fits much more to the lazy American driving style, and at the same time you can floor it, if you want to go fast, and you hardly need an autobox to achieve that)

Ah but low-end grunt isn't the exclusive province of diesel cars, is it

However your average atmo petrol engine doesn't require the added complexity of a turbo (oops, two turbos) to also deliver good 'high-rpm' performance, as do diesels. By that - and if I could use your car as an example - I'm guessing the attainable max speed (ie max revs) of 1st gear on your super-Citroen would pale against the max speed - and therefore lack the in-gear breadth of useability - of what is obtainable in 1st from everyday stock-standard Oz petrol cars - if I could use those as an example

Eg regular atmo Falcon 6cyl manuals have similar horsepower to your (modified) C5, and more than enough torque to 'bag it up' off the line, yet typically produce around 85 km/h in 1st gear. In comparison what would the UCP Express top out at in 1st?

And you may remember that Commodore (Holden V8) manual which I recently almost bought (sob). In that car the useable in-gear speeds in 2nd extended down from about 12 km/h, up to 110 km/h. And 3rd gear stretched from approx 20 km/h to over 160 ... which is an impressive (and genuinely useable) in-gear spread of 140 km/h!

In light of the above, where is the diesel 'advantage' in driveability

[LeonOfTheDead]

In light of the above, where is the diesel 'advantage' in driveability

he is going to say "mileage", and it's impossible not to agree on that.
the performance delivered by a diesel could be matched by a lot of other cars, even smaller in displacement than those you pointed out, but the mileage of a diesel and good performing car are matched basically only by a small petrol hatch driven responsibly too.

[Waugh-terfall]

No grin or smile whatsoever. Even if it could sit at 200km/h all day with ease.

It's very efficient and frugal but it just isn't exciting. You don't drop a couple of gears and floor it just for fun. That's a big part I miss and it makes it almost boring. Almost.

Best saving for the 135i Coupe

[Kitdy]

Kitdy: Statistics and lies. May be for the forum population you may have point, but how many here have driven a 200 plus BHP diesel car? (and please don't mention a truck or tractor)

That's a good point.

Another interesting angle would be performance Diesel - (TT TDI?) vs performance gasoline? How many have driven both? Not many really.

I still think though that to an extent, the market shows that diesels are most favoured where gas is expensive which while not entirely indicative of Diesels strictly being the economical choice certainly says something about consumer's thoughts when it comes to what car they buy.

The fact that this is an enthusiast forum and not many of the forum prefer diesels is also telling - I know not too many have driven the 200+ hp cars you bring up but it still once again is evidence.

Interesting none the less - I can also see this is turning into hit the diesel fan with a piñata as it's about 4-1.

You never did answer if you had driven comparable Otto C5s.

[Ferrer]

Best saving for the 135i Coupe

That has to be one of the best performance bargains out there. A shame they don't make it as a hatch.

Another interesting angle would be performance Diesel - (TT TDI?) vs performance gasoline? How many have driven both? Not many really.

I still think though that to an extent, the market shows that diesels are most favoured where gas is expensive which while not entirely indicative of Diesels strictly being the economical choice certainly says something about consumer's thoughts when it comes to what car they buy.

The fact that this is an enthusiast forum and not many of the forum prefer diesels is also telling - I know not too many have driven the 200+ hp cars you bring up but it still once again is evidence.

It's not about the performance for me. Diesels can be very fast indeed, and as Damiano pointed out it's impossible to argue with the fuel savings. But there's no passion, no soul no real drama. That's personally what I miss when I drive a diesel. And that's why I prefer petrol engines, even if they are slower.

[Ferrer]

Of course we speak from an European point of view. And that's what I have:

95 Unleaded -> 0,95€/litre
Diesel -------> 0,90€/litre

Now the BMW 118d (143bhp, 4 cyl diesel) can do about 6l/100km and the Mini (170bhp, 4 cyl petrol) does about 10l/100km.

So in the BMW for every € spent in fuel I can do 18,5km, whereas in the Mini I can only do 10,5km.

[LeonOfTheDead]

I find it's pointless to compare a 14 years old car to a modern one. I could say on original Fiat 500 consumes even less, but that's meaningless, even if compared to a modern 500. they are two completely different cars, and being on the market for the cheaper but still interesting car, perhaps for commuting, I would require generally some level of modern stuff and a decent reliability that usually a new car can better provide rather than an older one.
let's say I'm my father, looking for a new car.
He drives quite a lot every year, at least 30.000 km, and he uses the car for work. Now let's say he is also a car enthusiast as I am, so he wants to buy the more interesting thing on the market among the typical choices for a mid-aged man.
LPG is surely cheap to run, but requires you to trade some space on your boot, and that's something he needs when working. it could still be a possibility.
diesel costs about as a petrol car converted to LPG ot buy, and has a similar mileage.
petrol cars are cheaper to buy, period, but they usually costs more per mile (or km).
Also, with so much miles per year, he is likely going to change the car after about 2 or 3 years, in order to have a fully working car and some nice extras they usually give him when buying a new car, like 24h assistance, free courtesy car (among request) and so on.
LPG is basically excluded by the boot issue, or the same if you are going to dismiss the spare tire, because running even 500 kms a day, it could be quite annoying to have a puncture and not a spare tire. especially, he works in hospital, so being late to work doesn't mean he won't be payed for that time, but that a surgery operation won't be performed, which is quite annoying.
a petrol is too much expensive to run, he already tried that, and he also tried LPG, but finally found a diesel was the best solution, as cheap as an LPG, as practical as a petrol car.

considering performance, I can remember the different behavior of the car when running on LPG instead of petrol, it was like having two (fat) passengers in the car. I also drove a modern LPG factory car (Fiat Punto) for a long trip. it was surelly not a performance oriented car, but again the differences when running on petrol where enormous.

So finally diesel comes as the best solution, cheap, fast, practical.
no matter if it isn't the enthusiast first choice, we are talking about saving money after all.

when considering performance oriented cars, even an LPG as too many trade offs IMO.

[nota]

he is going to say "mileage", and it's impossible not to agree on that.

Yep I fully expect it

as Damiano pointed out it's impossible to argue with the fuel savings.

Well this is an international forum and thus reality can be a fickle thing, as in the Euro reality vs our version of same. Hence your collective mandate of "impossible not to agree" becomes in Oz an effortless challenge, through OUR reality of fuel price structuring

Prices do fluctuate, but over here a litre of diesel generally costs rather more than petrol, and of course waaay above LPG. The reason for this being our fuel prices are divorced from the European context and instead derived elsewhere (either based on the Singapore market (MOPS95) or Malaysian TAPIS) which in recent years have been greatly affected by increasing Chinese demand for diesel. For example, before the GFC hit, China's regular monthly growth in demand for diesel exceeded Australia's total annual consumption! Thus diesel typically becomes an expensive fuel alternative, both to petrol and especially to LPG. And note this disregards the substantial price-premium imposed on diesel-engined cars over their petrol-powered versions. Both factors collude to make diesel of either little to no economic advantage to petrol, or simply uneconomic to petrol, and of course totally uncompetitive against LPG

As mentioned, prices do wax & wane, as have the relative differences between the different fuels. But to give you a recent example (over X-mas IIRC) I noticed these approx per-litre prices at my local servo

$0.60 > LPG
$1.10 > 91 unleaded
$1.60 > diesel

On a cost-per-mile basis the above prices *might* translate to a 4cyl diesel Citroen @ 60 mpg hwy = 100 kms for $7.52 spent

Or a ($10k+ cheaper to purchase) 4cyl petrol Citroen @ 40 mpg hwy (guess) = 100 kms for $7.76 spent

Or perhaps the above petrol Citroen converted to LPG @ 34 mpg (guess) = 100 kms for $4.95 spent

And even that ancient 1994 Holden V8 (after LPG conversion) @ 27 mpg hwy = 100 kms for $6.27 spent


( *might* = amended late nite posting, so here's hoping! )

[LeonOfTheDead]

don't know how it happened, but my previous post was supposed to be after Nota's one, so here is the right order.

Yep I fully expect it

Well this is an international forum and thus reality can be a fickle thing, as in the Euro reality vs our version of same. Hence your collective mandate of "impossible not to agree" becomes in Oz an effortless challenge, through OUR reality of fuel price structuring

Prices do fluctuate, but over here a litre of diesel generally costs rather more than petrol, and of course waaay above LPG. The reason for this being our fuel prices are divorced from the European context and instead derived elsewhere (either based on the Singapore market (MOPS95) or Malaysian TAPIS) which in recent years have been greatly affected by increasing Chinese demand for diesel. For example, before the GFC hit, China's regular monthly growth in demand for diesel exceeded Australia's total annual consumption! Thus diesel typically becomes an expensive fuel alternative, both to petrol and especially to LPG. And note this disregards the substantial price-premium imposed on diesel-engined cars over their petrol-powered versions. Both factors collude to make diesel of either little to no economic advantage to petrol, or simply uneconomic to petrol, and of course totally uncompetitive against LPG

As mentioned, prices do wax & wane, as have the relative differences between the different fuels. But to give you a recent example (over X-mas IIRC) I noticed these approx per-litre prices at my local servo

$0.60 > LPG
$1.10 > 91 unleaded
$1.60 > diesel

On a cost-per-mile basis the above prices *might* translate to a 4cyl diesel Citroen @ 60 mpg hwy = 100 kms for $7.52 spent

Or a ($10k+ cheaper to purchase) 4cyl petrol Citroen @ 40 mpg hwy (guess) = 100 kms for $7.76 spent

Or perhaps the above petrol Citroen converted to LPG @ 34 mpg (guess) = 100 kms for $4.95 spent

And even that ancient 1994 Holden V8 (after LPG conversion) @ 27 mpg hwy = 100 kms for $6.27 spent


( *might* = amended late nite posting, so here's hoping! )

I find it's pointless to compare a 14 years old car to a modern one. I could say on original Fiat 500 consumes even less, but that's meaningless, even if compared to a modern 500. they are two completely different cars, and being on the market for the cheaper but still interesting car, perhaps for commuting, I would require generally some level of modern stuff and a decent reliability that usually a new car can better provide rather than an older one.
let's say I'm my father, looking for a new car.
He drives quite a lot every year, at least 30.000 km, and he uses the car for work. Now let's say he is also a car enthusiast as I am, so he wants to buy the more interesting thing on the market among the typical choices for a mid-aged man.
LPG is surely cheap to run, but requires you to trade some space on your boot, and that's something he needs when working. it could still be a possibility.
diesel costs about as a petrol car converted to LPG ot buy, and has a similar mileage.
petrol cars are cheaper to buy, period, but they usually costs more per mile (or km).
Also, with so much miles per year, he is likely going to change the car after about 2 or 3 years, in order to have a fully working car and some nice extras they usually give him when buying a new car, like 24h assistance, free courtesy car (among request) and so on.
LPG is basically excluded by the boot issue, or the same if you are going to dismiss the spare tire, because running even 500 kms a day, it could be quite annoying to have a puncture and not a spare tire. especially, he works in hospital, so being late to work doesn't mean he won't be payed for that time, but that a surgery operation won't be performed, which is quite annoying.
a petrol is too much expensive to run, he already tried that, and he also tried LPG, but finally found a diesel was the best solution, as cheap as an LPG, as practical as a petrol car.

considering performance, I can remember the different behavior of the car when running on LPG instead of petrol, it was like having two (fat) passengers in the car. I also drove a modern LPG factory car (Fiat Punto) for a long trip. it was surelly not a performance oriented car, but again the differences when running on petrol where enormous.

So finally diesel comes as the best solution, cheap, fast, practical.
no matter if it isn't the enthusiast first choice, we are talking about saving money after all.

when considering performance oriented cars, even an LPG as too many trade offs IMO.

[Ferrer]

Yep mine was supposed to go after nota's as well...

[Kitdy]

And that's why I prefer petrol engines, even if they are slower.

But per price and per displacement, they aren't slower - they are typically faster.

[Ferrer]

But per price and per displacement, they aren't slower - they are typically faster.

Don't be so sure.

The BMW 123d (204bhp 2 litre turbo diesel) is faster to 100km/h than the Seat Leon FR (200bhp 2 litre turbo petrol), 6"9 seconds v 7"3 seconds. It also has a higher top speed, 238km/h v 229km/h.

As for the same price, the 118i and 118d cost about the same (200€ of difference) and they perform about the same in acceleration and top speed (same top speed, the petrol is 2 tenths of a second faster to 100km/h). However when going from 80 to 120km/h in 4th the diesel is 1"3 seconds faster than the petrol.

[Kitdy]

Fair, but I'd bet that diesel is much more stressed then the gasoline version and I'd be right. Also if I want to be a dick about it, compare like with like: a turbocharged gasoline with a turbocharged diesel - then there is no contest whatsoever, or a naturally aspirated diesel with a naturally aspirated gasoline engine. If you want to complain about the fuel discrepancy comparing a turbo diesel to a turbo gasoline, the turbo actually makes the engine more efficient and though it does increase fuel consumption, it would do so to a small degree I believe (could someone correct me on this if I am wrong?)

Also, does that sort of diesel performance scale up to large engines? I am not so sure. I would posit that diesels may be running much more stressed and to the limit of performance in even relatively pedestrian applications like your BMW so when it comes to performance variants of diesel there may not be much more room to eke out power. This is sheer speculation however.

I am strictly being the devil's advocate here though.

[nota]

don't know how it happened, but my previous post was supposed to be after Nota's one, so here is the right order.

I committed a major stuff up with my calcs and had to delete and repost after amendment. Sorry about that guys!

Let's say I'm my father, looking for a new car.
He drives quite a lot every year, at least 30.000 km, and he uses the car for work. Now let's say he is also a car enthusiast as I am, so he wants to buy the more interesting thing on the market among the typical choices for a mid-aged man.
LPG is surely cheap to run, but requires you to trade some space on your boot, and that's something he needs when working. it could still be a possibility.
diesel costs about as a petrol car converted to LPG ot buy, and has a similar mileage.
petrol cars are cheaper to buy, period, but they usually costs more per mile (or km).
Also, with so much miles per year, he is likely going to change the car after about 2 or 3 years, in order to have a fully working car and some nice extras they usually give him when buying a new car, like 24h assistance, free courtesy car (among request) and so on.
LPG is basically excluded by the boot issue, or the same if you are going to dismiss the spare tire, because running even 500 kms a day, it could be quite annoying to have a puncture and not a spare tire. especially, he works in hospital, so being late to work doesn't mean he won't be payed for that time, but that a surgery operation won't be performed, which is quite annoying.
a petrol is too much expensive to run, he already tried that, and he also tried LPG, but finally found a diesel was the best solution, as cheap as an LPG, as practical as a petrol car.

Sydney-based 'Wheels' magazine recently published an interesting comparo last November, between LPG Holden & Falcon (6cyls) and the new cylinder-shutoff Honda Accord V6 petrol. During the test their test region's fuel prices were 0.65c p/l for LPG and $1.50 for 91 petrol. (Diesel was more expensive again)

So lets presume your Dad lives in Oz and sells after 100,00kms when the factory warranty expires. And he is (hypothetically) interested in a family-sized sedan, as above.

There were various strengths & weaknesses between each of the vehicles. For example the Honda boot holds 450 litres, while LPG reduces the Falcon boot to a mere 408 litres

But here's the bottom line:

100,000 kms in the Honda would work out at $16,500.
The same distance by Holden equates to under $9,500 - thats a considerable $7k+ saving, representing 20~25% of new car price...


Unfortunately no diesel was included in their comparison. However it seems that an equivalent diesel car would be less competitive in either price, or performance, or fuel cost per mile - or a combination of the above.

Interesting to compare the annual emissions @ 20,000 kms travelled
("based on Wheels fuel road test fuel consumption. LPG = 15.0 grams of CO2/km. 91 RON petrol = 23.8 grams of CO2/km")

5.24 tonnes: Honda petrol
4.77 tonnes: Ford LPG
4.34 tonnes: Holden LPG

[nota]

Fair, but I'd bet that diesel is much more stressed then the gasoline version and I'd be right. Also if I want to be a dick about it, compare like with like: a turbocharged gasoline with a turbocharged diesel - then there is no contest whatsoever, or a naturally aspirated diesel with a naturally aspirated gasoline engine. If you want to complain about the fuel discrepancy comparing a turbo diesel to a turbo gasoline, the turbo actually makes the engine more efficient and though it does increase fuel consumption, it would do so to a small degree I believe (could someone correct me on this if I am wrong?)

Anecdotely I read (and hear) that the new crop of small capacity diesels in modern passenger-cars & small-pickups (as distinct from the true truck-type motors) have sacrificed strength for less weight, and typically don't outlast petrol engines - if that

And they're considerably more expensive to recondition....

Adding a turbo to diesels actually improves economy afaik, and has had the same benefit to certain petrol engines IF strictly driven for economy. Road tests recently cited a mere 7.3 L/100km during steady-state hwy cruising in the 310kw FPV F6 (turbo I-6) which is a figure I doubt you would see from the atmo version