New VW Diesel Could Match Hybrid Mileage

Around 100,000 euros, just a little more than the bmw i8. When they are in production I can't see many choosing the XL1 over the i8 or Tesla S. It will be a collector's car. The XL1 if it is popular will get another version, but its more interesting as a concept than a car to own.

I hadn't heard of them, now I know why, they had no chance of making it.
The Continental: Stratos Details, Loremo Finished, and Where Your Real Musical Taste Comes Out | Car and Driver Blog

 

Throwing around numbers for Prius efficiency (38%) and TDI Efficiency (42%), considering around 10% more energy in diesel, considering more drive train loss in Prius, latest aerodynamic tweaks of the VW bluemotion, the highway difference should be much more in favour of TDI, more than speed vs. MPG graphs suggest.

Why is that not so?

Are those efficiency numbers without catalytic converter, SCR, DPF ...?

Try to play around with this tool, and if I punch in there .42 engine efficiency, no. 2 diesel fuel, use .95 drive train efficiency, use high cd of .30 and I get unrealistic 75 MPG at 60 mph. Try the same with Prius .38 engine efficiency, .93 drive train, summer gasoline fuel, .25 cd and I get around 66 MPG at 60 mph, still exaggerated but not that much.

Does exhaust gas treatment cost 25% of diesel engine efficiency and less than 10% in gasoline engine? Or is the TDI reving to high with fixed gear ratios, it's reving with less than 2.000 rpm at 60 mph, is that to high? Maybe 2.0 is just to big engine for efficient 60 MPH (low load), maybe 1.4 TDI would get 75 MPG at 60 mph?

 

Most VW diesels find their prime torque between 1800-4000 RPM.

cf. TDI Fuel Economy - TDIClub Forums

 

It turns on how many EV's there are with fully expensed roof top solar

 

The numbers are without emissions, except maybe EGR. Then the type of emissions control makes a difference. SCR is best if you don't want to sacrifice fuel efficiency. The TDI Jetta and Passat use the same engine. The Jetta uses NOx trap and the Passat SCR. Despite the size difference, they are close in EPA ratings.

Gasoline emission controls are a far more mature technology. When first required, the power output and efficiency dropped. Even in the '90s and early 2000s, when manufacturers offered different engines for CARB and federal states, there was a difference in horsepower between them. Possibly as high a 10hp more for the federal.

Then diesel owners also claim that the EPA under estimates fuel economy. There are a some at cleanmpg, and diesels are lusted there for their higher potential in mpg.

 

Our models don't have any of the aero tweaks or other stuff from the Bluemotion models.

 

But I've seen many diesel engines spec'ed at do not exceed 1600 RPM or 1900 in other applications for long hours of use. Are auto diesels so different?

 

Were those turbos?

 

How big were those engines? Big engines generally have lower rpm limits.

 

It looks like peak efficiency is around 80% load 2300 rpm. This is much too much power for 60 mph though. If you are cruising at 60 mph, 1500 -2000 is likely most efficient, while still providing good headroom for acceleration. IIRC the top gear will put the engine near the top of that range. The ice will become more efficient at higher speeds, but aerodynamic drag increases also, making the car get lower mpg.

Brake Specific Fuel Consumption (BSFC) Maps - EcoModder

 

This is a good point. If the Jetta had the design and Cd of say, a LEAF, then 60-65+mpg would be no problem.
Only with a comparable Cd do comparisons of highway mpg vs. the Prius make sense, in both cost-per-mile and emissions-per-mile.

 

I assumed we were/are referring to diesel passenger cars. The VW TDi vehicles use a turbo (Garrett VNT15). The max torque ranges from 1800-4000RPM.

 

http://www.youtube.com/watch?feature=player_detailpage&v=LZqjqCmhE_Q&t=3

 

Please don't conflate legacy diesels (pre-2007) with new-technology diesels (i.e., "clean diesel"); there's a tremendous difference in emission rates.

Here's a demonstration of a pre-2007 diesel school bus retrofitted with a DPF...

(note especially @3:32 - 3:58 mark)

Regarding the carcinogenicity of gasoline engine exhaust, direct from IARC (an agency of WHO)...

International Agency for Research on Cancer. 1989. “Diesel and gasoline engine exhausts and some nitroarenes.” IARC. Vol. 46: 88-185, Appendix A-2…Epidemiology studies of carcinogenicity to humans. http://ntp.niehs.nih.gov/ntp/newhomeroc/other_background/DieselExhaust_508.pdf (Page 99 (103 of 196))

 

Post 81 of this thread, wxman showed the data for well to wheels emissions between the Passat TDI and its PZEV gasser kin. The TDI was cleaner. Even when just looking at vehicle emissions, the TDI was cleaner in 2 of the 4 tested emissions. Particulates was one of them.

These are numbers for the US. The article is concerning the UK. Their diesel emission regulations won't be as strict as the US is for over a year. So they will be dirtier. The data is also concerning the emissions of their fleet. Which has far more more diesels the US in the mix. It will also include older diesels that were made to standards less strict than they are now. They will eventually be replaced with a cleaner diesel or other type of fuel.

So, when the diesels are dirtier, and there are far more of them, their contributions to the fleet emissions will be far greater. If the UK had the same mix of petrol and diesel vehicles as the US, this clean air group might be calling for the ban of petrol cars because of the benzene instead. They would probably also consider the fact that the particulates for petrol cars are smaller, and can get deeper into the lungs.

 

It's probably key to realize how different the US is from Europe in diesel. This is a UK study, and even in 2015 when euro 6 kicks in, diesel emissions in europe will still be higher than the US.

Post 2010 all new light and heavy diesel vehicles sold in the US have particulate and NOx restrictions that are much lower than pre 2006 levels when ultra low sulfur diesel standard kicked in to allow for pollution control. There are still these older cars and trucks on the road, but they are a much smaller percentage than in europe, and no new ones have been sold for a very long time.

 

But our cars (including diesel) are much more fuel efficient by a significant margin. Therefore would our collective emissions be less than a similar number of less fuel efficient US cars?

I always wondered this. Twenty European cars with an average fuel economy of 40 mpg US against twenty US cars with marginally stricter emissions but almost half the fuel economy?

 

Emissions are measured at an amount per mile. If the US car has a lower g/mile than a European car, then it is polluting less regardless of fuel economy. The only emission linked directly to fuel economy is CO2. NOx has some correlation to fuel economy. A lean air fuel mixture will improve economy while producing more NOx. There are strategies to controlling the NOx produced, but not for CO2.

Driving styles and routes might have different emissions than the tested results. Speeding under at wide open throttle might increase hydrocarbons since most cars inject extra fuel for a cooling effect under those conditions. Short trips will be the bigger change than tested. Emissions will be higher with a cold engine and catalytic convertor. Isn't the average trip length shorter in the UK than the US?

 

Here in Europe CO2 is the only number people are looking at, because there are extra purchase taxes on CO2 or insurance or a yearly fee ... CO2 is the main and only enemy in our heads, but only because it costs us money.

Main problem with diesels will always be emission filters, the average car on the road is old (7-10 years). I don't know for the rest of Europe but here where I live you can have DPF removed and ECU remaped, you will have lover fuel consumption and no one can detect that you removed DPF, inspection just doesn't have the equipment to detect it.

Data for well to wheels emissions, will be different for country to country, refinery to refinery. In US where there is little demand for diesel fuel and you must sell the excess to Europe and your refineries are maximizing gasoline, obviously this costs energy. I think the situations in Europe is reversed with consumption of diesel vs gasoline at 75:25, the refiners will try to maximize diesel yield, and this again costs more energy to produce, am I missing something here?

 

Don't they do an visual inspection? A Civic VX owner on another forum recently failed emissions in California. The tested numbers were fine, but since it have an after market catalytic convertor installed after the original, it failed for having modified emissions.

There is also a petroleum source variance. The light, sweet stuff is mostly gone. So the amount of gasoline that can simply be distilled off from the crude is low. Plus, it is too low of an octane for modern engines. To meet gasoline demand, there will always be cracking of longer hydrocarbon chains and reforming of smaller ones from the crude.
Diesel on the other hand makes up a larger portion of the crude. So, if required, there will be less cracking and reforming than with gasoline production. It might only need to have the sulphur removed before being usable in a car engine. At this point making diesel is less energy intensive than making gasoline.