There's no doubt at all that a diesel car has the potential to be considerably better than a petrol/hybrid.
In response to Porkyd and his comments on the false claims about diesel cars, I've run an Audi A2 1.2Tdi 3L for 7 years now. The A2 isn't much smaller than a Prius and probably has much better use of space and, therefore, capacity. It's certainly not a small car.
My A2 averages between 90 and 96mpg (UK) and has given me 120.2mpg (UK) on a door to door trip from my home in Yorkshire to London - including the town driving at either end. I can very easily exceed 100mpg on any long run.
Show me a Prius that can match that!
The (very) sad thing is that my 7 year old car (a model only sold in Germany) was discontinued by Audi some years ago because "no one ever bought them" and "they never made any money on them". In fact, they didn't charge enough money for them. I bought mine in Germany for 3000 pounds less than the standard A2 was on sale in the UK. There doesn't seem any will within the motor industry to tackle the emissions problem. the technology's been around for years but I'd place a bet on the new A2 (coming in 2011) having much poorer consumption figures than my 7 year old car with 105,000 miles on the clock!
I went from a Peugeot 2.0l HDI 110hp to a PriusIII > 130hp and I consume less gas than I used to consume diesel.
And you shall not forget that one litre of diesel rejects more CO2 than the same amount of gas, so that the difference in CO2 is even more important.
But what is nasty with small diesels is that they often do not have particulate filters nor NOx filters, and this is an issue in cities where diesel cars are really a nuisance (not so on highways, but who does only highway driving with his car?).
I'm still confused by all this N0X stuff, if you look at the N0X emissions for Europe, they are so much lower than in America. And most cars have DPF fitted as standard.
My only guess is that because fuel in the US is so "dirty" and unrefined compared to the liquid gold we make in Europe, that somehow when a clean Euro diesel is tested in the US with US diesel in it, it somehow emits more N0X as there are more harmful pollutants in the US fuel to start with.
We just lowered the sulfer content in Diesels here in the US a few years ago. We had to that first before we could use the new emmisions that are now on the cars. So I don't know how dirty our fuel is now compaired to Europe but it should be alot closer to you. Here in the US we refine diesel here and send it to Europe! LOL!
I don't think diesels can achieve much else beyond a small niche market share here in the US. Our emissions controls just don't allow the automakers to bring small diesels to market. Given the governmental controls most automakers will continue down the hybrid route this side of the Atlantic.
The smaller cars don't have to have the expensive Urea treatment, VW's jettas and Golfs don't need it but if you get into larger engines you will need them. I won't go hybrid at all unless it comes with a diesel motor! LOL!
The fact that diesel produces about 15% more CO2 than gasoline (gallon for gallon burnt) means that a 40mpg TDI Jetta produces about as much CO2 as a 34mpg Corolla. A 55mpg Prius emits about 40% less CO2 per mile than a 40mpg TDI Jetta. CO2 restriction is where most civilized nations are heading with emissions controls, that will play a large part. The extra expense of a diesel engine is the other barrier -- though I don't see how VW can justify the price of German/Mexican Corollas, diesel or no diesel.
I would love to see anyone sell a diesel microcar in the US. It might fail miserably like the Smart car has, but it might be mildly successful too. I would think about buying one. But not a 60hp diesel four-door that goes 0-60 in 15 seconds like the A2. That would never sell here. I am looking forward to the American version of the iQ. That's a car I'd consider buying, as long we get the 1.3l and a manual transmission.
I pull a small trailer with my jetta and still get in the 40's mpg on the highway. I can get 32mpg pulling a 13 ft boston whaler with 4 people. For me Diesel can do more and I love the power at 1200 rpm and that is with my old 01 Jetta that is not clean. I just don't like the Prius. Pretty much boring to me. I can hop up the power on my car with cluch ripping force and still get the same milage. Power and good milage is what I like! LOL! There are going to be different cars for different people and peoples needs. Still wanting a Jeep Wrangler 4 door with Diesel and would go hybrid if they do decide to go with the diesel hybrid!
You're all forgetting about the new strict Euro emission standards, diesels are getting cleaner and cleaner and more powerful. Last time i researched this, i found that the N0X emissions have been much lower in Europe for years than in California, by around 5 to 6 times, and i triple checked my calculations too. I think the controversy surrounding this and all the confusion can only lead to one conclusion - the US has developed a conspiracy theory that somehow a tiny clean efficient diesel car from Europe that does upwards of 100 MPG can somehow emit more N0X than an 8.0 litre Yank tank that barely reaches double figures!? C'mon guys, common sense needed...