New VW Diesel Could Match Hybrid Mileage

Then except for the people who live exclusively on highways what conclusion about frugality can we draw ?

Unless of course regulatory agency numbers are used.

 

I am simply providing data that I know, I don't have all the answers and can't tell you what conclusions to draw. Use fuelly, use the EPA, take both out for a test drive on the same loop, read magazine comparisons, use Consumer Reports, there are a number of ways you could compare the two if you wish. FWIW my average speed over the course of a tank is usually in the 35-45mph range and average mpg is in the 40-50 range.

 

We have to realize that a Prius vs VW TDI comparison is not a hybrid vs. diesel comparison. The Prius is not just a hybrid; it's a hybrid where every effort has been made to improve fuel economy -- superb aerodynamics, LRR tires standard, electric power steering, no accessory belts, weight reductions, 0W20 engine oil, etc. We would have to drop a stop-start, turbocharged, probably 3-cylinder, piezo injector, common rail diesel into a Prius chassis to make a comparison.

Interestingly, there are throttle-less gasoline ICE's on the market -- BMW's for one and FIAT's FIRE engine [sic] for another. The FIAT claims a "Mulit-Air" valve timing feature which in effect makes the power stroke longer than the intake stroke creating a different sort of pseudo Atkinson effect.

It's all great stuff - we as a world need better transportation fuel economy.

 

What about Japan? That is Mazda's home market.
I was going by Mazda's statement regarding diesel emissions and the US.
BBC - Autos - Mazda prepares US diesel invasion
"The difficulty, and frankly, the delay for US sales relates to the quality of the fuel. “The cetane number is low, which means the fuel itself has less ability to auto-ignite,” Ishino said. The challenge for Mazda is to ensure the engine starts up without difficulty and still controls soot and NOx in such conditions, because the diesel formulation in the US will not change for the sake of accommodating a clever engine."
In other words, "US diesel is crap."
This was also in the linked article. "It passes EU emissions restrictions that will not be enacted for another few years." Which means Euro VI, that are equivalent to current US standards.

I am unfamiliar with Australia emission laws. Is regular testing a requirement? There is a subset of the diesel crowd that likes smoke, and will defeat the emissions equipment for the smoke. Some will also do it for more power or increased efficiency. They were upset when Ford made in harder to defeat emissions when their new engine came out a few years ago.

It's a shame. Diesel has a part to play in reducing petroleum usage, and biodiesel has potential (and it produces less particulates). This subset just gives diesel a bad name with the rest of the population. The other week I was behind an '80s era truck with the upright exhausts, and you literally couldn't see the truck through the smoke during acceleration. I haven't notice smoking from a recent model year diesel though, but they are less common than hybrids and hard to spot from the gas model.
That said, I've come across the stink of a polluting gas car more often than a diesel.

That's simple. Wane Gerde's graphs are made from steady state speed of cruise control at the stated speed. They go down 45mph or even 40mph. Why not lower? Not every factory cruise control will actually engage at lower speeds. Without cruise control, you introduce too much variability from the driver. The testing is also done on surface streets. So, if cruise will work at those speeds, you need a road where you can safely go at that speed long enough to get a steady state consumption reading.
Wayne and other hypermilers driving diesels have conceeded that hybrids rule in stop and go city driving.
At least here, the roads that have few enough lights not to become stop and go are 40mpg and above.

Mazda's capacitor regen system, iEloop, is available on the new Mazda6. The numbers are now up on the EPA site. The M6 with automatic is rated 26city/38hwy/30combined. With iEloop, the numbers are 2mpg higher across the board.

The diesel won't arrive until the second quarter, and no other details on its features are forth coming. I haven't heard of any reason why the iEloop would not work with the diesel.

 

Clarksburg, WV

cm_tenderloin ? 2

 

There aren't much data specifically for the Prius, but there are quite a bit of data showing that particle emissions from current-technology diesels are less than gasoline vehicles in general.

Argonne National Laboratory (ANL) measured emissions from a 2009 Jetta TDI. The PM emissions were barely measurable, and under some circumstances, couldn't be measured at all, even with the most sensitive gravimetric instrumentation available...





Source:
http://www1.eere.energy.gov/vehiclesandfuels/pdfs/deer_2010/thursday/presentations/deer10_shaburg.pdf (Slide #9)


Gasoline cars typically emit around 1 mg/mile in the FTP, according to CARB. Note that the PM emissions in the US06 cycle were less than detection limits for ULSD. US06 duty cycle is the "aggressive" test cycle using high acceleration rates and relatively high max speed points.


Particle number (PN) emissions from diesel cars with DPF have been shown to be orders-of-magnitude lower than gasoline cars...



Source: Ecotraffic Report, "Particle and NOx emissions from automotive diesel and petrol engines - A 2009 update." (Figure 10 on page 33)


Particle emissions from gasoline direct injection (GDI) vehicles (e.g., Ford's "Ecoboost") have have been shown to have particle emissions that rival unfiltered diesels. This has lead to some concern that PM emission inventories will backslide as more and more manufacturers go to GDI in an attempt to improve fuel mileage. Just because you cannot "see" the particles doesn't necessarily mean that they're not there.

 

I wasn't commenting on the review at all. I was commenting on some of the replies. Seems like some people really dislike (that better?) diesels. The only hybrid I've driven is the Prius and I can see why it isn't for everyone. Diesels aren't for everyone either. Can't we accept both as higher mileage replacements to ordinary gassers?

 

Cruze diesel for example has 19 mpg difference between city 27 & highway 46, and the mileage of a cold engine from driveway to city driving before reaching the highway is averaged ........

 

Hopefully you can understand why it is frustrating when people conflate "hybrid" with "Prius".
You did not do that in your post, but you also went on to say that "diesels aren't for everyone".

The main problem, as I see it, is that people are conflating a particular technology (diesel, hybrid, etc.) with the first car to use it in large numbers, or the car that was very successful in meeting its design goals.

Think "Hybrid", what comes to mind? Prius
Think "Diesel", what comes to mind? Jetta
Think "Natural Gas", what comes to mind? Civic

Thus people tend to fall into the trap of assuming that all cars that have that particular technology will perform exactly as the car they are thinking of. So, hybrids are "slow and boring", diesels are "fun and torquey" and so on

We need to accept that hybrids span the full range in price, performance and luxury - from Honda Insight all they way t0 LaFerrari.
We need to accept the same with diesels and all other fuels, and keep an open mind.

I drive a Prius, but I would not write off all diesels, because I know that the technology encompasses a wide range of models with different performance, characteristics from a Golf TDI to a Q7.

Personally, I would rather have a VX XL1 than my Prius.

 

That's because the Cruze platform is a little porker like many of GM's. Weight hurts city economy more than highway with all the slow downs and speed ups. Aerodynamics have a bigger role at highway speeds. There the diesel Cruze has all the tweaks, like active grill shutters, that the Eco Cruze has.

The new platform will take better advantage of weight saving technology. So the city numbers should improve.

Another reason for the relatively wider spread is that a diesel engine can have a wider fuel consumption spread than a gasoline engine. Both use more fuel under load. At lighter loads, such as idling or cruising at a set speed, the diesel engine has an efficiency advantage in not having a throttle plate. When at the partial throttle of a light load, a low pressure, or vacuum, condition is present in the gasoline engine intake manifold. Pumping losses are caused by this vacuum, because the pistons are trying to pull against it. No throttle plate, means no pumping losses caused by it for the diesel.

 

Cruze = porker, but a cash cow for GM. The Volt = problem child.

DBCassidy

 

Misrepresentation raises my hackles. Read the title of this thread for an example.

As for diesel itself:

• I dislike the smell
• I worry about pollution from a car not 'tuned up'
• I want the best emissions profile
• I want the best *combined* fuel economy
• I want nothing to do with VW unreliability or sky-high maintenance costs
• I very much appreciate knowing that Toyota will likely back me if I have a legitimate gripe
• I appreciate Toyota's (relatively) responsible environmental conduct as a manufacturing company
• I appreciate the fact that Toyota and Honda developed hybrids on their own dime a decade before Ford/GM woke up.

 

^^^^^
Also, don't want additional maintenance items in a car; DPM and DEF fluid, and maybe other things!
Diesel fumes carcinogenic: WHO - ABC News (Australian Broadcasting Corporation)

 

Should one also install some sort of vacuum gauge to verify that the intake manifold reaches normal operating levels? Even with the plate closed, the first intake stroke of the test will be at full atmospheric pressure. A number of pumping strokes will be needed to evacuate the manifold, and the crankcase of a 2-stroke engine. And if the test does not reach normal operating RPM, a representative level of vacuum may never be reached.

 

When was the last time you smelled road diesel? I picked up a can of ULSD for our heating system between fills. The diesel smell of old is gone.

The emissions controls can by bypassed or defeated of gas cars can be defeated also, and there are more of them. The 'riced out' cars I see with fart cans on the exhaust and soot on the bumper aren't diesels.

A diesel now can be as clean as the cleanest gas cars. Just as gas cars can be as dirty as a diesel at T2B5. Which is stricter than the emissions from the '90s.

Toyota has no problem selling diesels in markets where the emissions standards are less strict.

Ford's hybrid program started with PNGV.

Toyota received aid from the Japanese government for the Prius.

 

The point is they aren't, despite the diesel tax-credits.

Show me a PZEV rated diesel available for purchase.

 

On the other hand, exposure to concentrated exhaust of a new-technology diesel truck engine has resulted in almost no health effects after 12 months of almost continuous exposure...

http://pubs.healtheffects.org/getfile.php?u=708

And apparently that trend has continued through the lifetime of the laboratory test animals...

http://www4.eere.energy.gov/vehiclesandfuels/resources/merit-review/sites/default/files/ace044_greenbaum_2013_o.pdf (Slide #19, last two bullets under "Status")

 

There are many things going on, and lower throttling losses are just one of them. The only way to really add them all up is experimentally, and bsfc graphs tell the story.

What you are feeling are pumping losses plus throttling losses when you are pulling that cord. Let more air in the engine, you need to pump more air out. Here we have more throttling losses on the gasoline engine, and more pumping losses on the diesel engine. It is time to look at the turbo. The turbocharger takes some of that energy of air pumped through the engine, and uses it to pump fresh air through an intercooler and into the engine. The turbos are not 100% efficient though, they become inefficient at high loads, and get bipassed at very low loads. Which leads to why the diesel is really more efficient at low loads, lean burn. A turbo diesel will be more thermally efficient, because it will use the fuel at higher compression levels. A gasoline engine might detonate, so lower compression and richer mixture is used at lower loads. In a direct injection engine a stratified charge allows it to get a little lean, but manufacturers don't want to add SCR for the small range of use. If you do the same air fuel ratio with gasoline as a fuel, the explosion gets very hot, causing detonation.

 

Not just Ford -- All the 'Big 3.'

Incorrect. The Japanese government subsided sales. A finished, marketed product.

In the US the subsidy works like this:

• Pay for the R&D, or just do the R&D at national labs and pay the auto companies for participation
• Bail out the company, and give the management huge bonuses for saving the company
• Pay to retool the factories
• Adopt the toxic dumps
• Subsidize sales