New VW Diesel Could Match Hybrid Mileage

They reckon diesels are fun to drive... I wonder in what way they are referring to? Is it because it shoots out black soot on heavy acceleration, or is it because it is shooting out cancer causing particulate matters? Low end torque is what they always brag about, but if you want a race car, diesels won't cut it... Look at this thread from Club Lexus Forum, Well the IS300h is no slouch! - Club Lexus Forums

IS300h won by a length at the end, even though the "official" figure suggests otherwise!

 

Yes, I get great fun out of contributing to cancer Funny that you say diesels don't cut it as race cars, there are a few that have done well such as the Audi and Peugeot endurance racers.

I just enjoy the ride, handling, and combination of mpg and turbo torque. Never made any black soot on heavy acceleration, if I did that would detract from my fun.

 

I've got to say they said hybrid not prius, and the new diesel may give hybrids a run for their moeny. Say someone is mostly a highway driver 25% city - 75% highway and they like manual transmissions. If this new beast gets 32/46 then combined it will be 41 mpg. That will best most hybrids. The camry hybrid is very efficient 43/39 but in that driving mix gets 40 mpg, 1 less than the tdi. Now the diesel fuel does have more energy, but these are efficient cars. Choice is good, and the new engine improves the tdi with more efficiency and more hp. Remember YMMV. Some will prefer the manual deisel (fun to drive), many other will like the eCVT (smooth). If you are a traffic jam driver hsd is supperior. If you are an open road driver, I would prefer a manual (but I am in a small minority and I drive 60% city, 40% highway)

 

The Passat diesel gets pretty impressive mileage as well ..well over the epa figures and that is substatiated by several reviewers Trip to the Coast, MPG Report - 2013 Volkswagen Passat TDI Long-Term Road Test

 

Volkswagen Passat MPG Reports | Fuelly (Diesel)

It looks competitive to a Prius v, but not a Prius Liftback. The wagon is not competitive with the v.
Toyota Prius MPG Reports | Fuelly (Liftback)
Toyota Prius v MPG Reports | Fuelly
Volkswagen Passat MPG Reports | Fuelly (Diesel wagon)

Even 7% improvement they talk about, 43 MPG to 46 MPG will not bring it even.

Fuelly is an inherently biased source, as owners that do not care about MPG do not report, but I can think of no reason it is not equally biased for every car.

(Austin Green quoted me as I was editing, he did not miss my text, I just had not posted my calculator math)

 

The article is about a new more efficient diesel that will be offered in the 2015 my. That should do better. Prius also is do for a redesign around then, so the new one of those will do better also. We should be happy about the new more efficient cars.

 

If you see a diesel shooting out black smoke, it is at least ten years old, and likely needs a tune up.

The DPF has taken care of the particulates. A diesel car made in the last decade emits less particulates from the tailpipe than the Prius.

Mazda is taking their 6 with diesel to the racing circuit, and has won.
Mazda runs diesel at Indy - Chicago Tribune

 

But the passat is not comparable to Prius HB. Much bigger car. Comparable to Camry

 

I am not who brought up the Passat, sorry.

 

Maybe they can design a high pressure fuel pump that doesn't prematurely fail to go with that new motor.

 

It is obvious that this upcoming diesel does not match up to the better hybrids, let alone the Prius, on environmental score alone. However at least in the US, for the vast majority of people emissions are not important and fuel economy is something of a middling priority at best. Actually, my impression is that people decide on an amount of money they are comfortable spending each month for fuel, and so long as the car they want falls in that money budget they consider the fuel economy 'good.'

In 2012 dollars, mainstream US consumers follow this rule of thumb:

Code:

Gas Price	Threshold MPG
2.0		20
3.0		30
4.0		40
....

 

I am wondering if just putting in some very basic regen functions ('mild hybrid') would help these diesels meet regs. without having to resort to exhaust after-treatment.
Also be interesting to see what the cost difference is between the two, as hybrid components are dropping in price.
It would seem to me that most of a diesel's emissions are during acceleration, so an electric boost would be a big help.
No need to even stop the engine at idle (if they can't figure out how to w/o clogging the filter.)
Just a simple hybrid system, low-cost, like Buick's E-assist..........would be interesting to see what emissions result.

 

The trouble some emission for diesel is NOx. The nature, and part of its efficiency, of the diesel has the the engine in lean burn under idle and light load. It probably isn't completely out of lean burn until full throttle. The high temperatures and lean fuel mixture are the perfect condition for NOx formation. The main reason for switching to ULSD was so that catalytic convertors could be installed on diesel vehicles to control NOx.

Particulates can be formed more readily while acceleration. This is simply because more fuel is being dumped into the cylinder. Soot forms when the the mix is too rich. The DPF takes care of it. On older diesels without a DPF, the excessive smoking is because the engine is out of tune. Some do this on purpose thinking the engine will produce more power. It's just wasting fuel.

The Skyactiv-D can already meet regs with the better diesel over seas without extra treatment. I think that means nothing more than what a gasoline car needs. The Mazda6 will also have a start/stop system and regenerative braking as options.

 

If by overseas you mean Europe, their emission limits are more lax than the US, in no small part to accommodate diesels. The EU continues to have one set of standards for diesel and another for petrol (from wikipedia):



So it is not a case of better diesels or higher quality fuel, it is simply lower standards. Euro6, slated to start late 2014, is reigning in diesel emissions although if I am reading the table correctly the regs are set up to let diesels trade Nox for HC or vice versa.

For giggles, compare the *future* Euro6 diesel limits to the Prius G3 from 2010:
CO 0.258
CO2 emissions 89 g/km
HC 0.058
Noise level 69 dB(A)
NOx 0.006

 

diesel = torque!

 

All the way up to ~ 40 mph or the next red light or car in front, whichever comes first.

Yaaaaawwwwn. Did diesel lovers not get a chance to suckle as infants ? They seem deprived.

 

Bottom line: if these diesel cars did not suck, there would not be a need to spin results like ignoring city MPG.

 

Parenthetically, this is the underlying reason why P&G works.

My arithmetic comes out a bit different though ...
The Prius uses say 5 kW to move the car through it's various frictions, and 1.1 kW to spin the ICE
The Diesel uses say the same 5 kW to move the car, but double the power to spin the ICE, 2.2 kW

Added up, the Prius advantage is 6.1/7.2 ~ 15 % less fuel. Yet the Prius in practice uses closer to 40% less fuel in urban driving, so I have always presumed other factors come into play. Diesels *should* do quite a bit better than regular petrol cars because they do not have air restriction, but somehow they disappoint. Too bad really. If diesels could match hybrids by just adding a start/stop ICE that allowed gliding at urban speeds, they would have a lease on life.