Re: so much misinformation in comments for Clean Diesel Cars Green than Hybrids - New Fuel Efficient

I replied like 10 msgs. I hope the moderator is not anti-hybrid / pro diesel and approve my msgs.

Re: so much misinformation in comments for Clean Diesel Cars Green than Hybrids - New Fuel Efficient

No need to get upset with folks who don't understand the difference between imperial MPGs and US MPGs.

Secondly they also don't realize that diesel fuel contains 17.5% more energy and weight per gallon than gas (gas has 15% less weight and energy per gallon than diesel). So it takes that much more crude to get diesel and that much more CO2 is produced from conbustion. Given the refining needs fro low sulphur diesel costs will get mor einterestign as well in the future.

DIesel engines have a couple of advantages over normal gas engines. They burn higher calorie fuel (see above), very high compression and are not throttled to minimize engine pumping losses. This typically gives them better fuel consumption as measured by the gallon. When the CO2 and actual weight/energy factor is taken out the difference is far less substantial for the similar type of vehicle, but they still have an advantage.

However hybrids does a lot mroe than just carry abattery, as in actual fact it allows the gas engine to operate in far more effective ranges vs non hybrid gasser. As such the diesel advantage vs a hybrid gasser in terms of engine efficiency is far less. Overall package will be more interesting, as all government (US/Euro) test shows that hybrids do outperfrom similar size diesels.

I can't wait for the clean diesels to get here if it allows some folks to get into high gas mileage vehicles with low emissions. Do we really care if somebdoy drive a Civic Hybrid vs a Prius??

It will also get diesels in the hands of the mainstream public, like hybrids now, and people will notice diesels are not the eutopia as articles like the link above promise. Tey do provide an advantages over normal gassers (only if they are clean diesels), similar ot hybrids, but niether is the promied land. Electric vehicles powered from renewable electricty will be much more like it.

Be long on accurate facts and short on opinion and life gets much easier.

This is the official UK guide to comsumption and pollution from cars. Quickly shows the flawed numbers prented in the article.
http://www.vcacarfueldata.org.uk/search/

Prius 65.7 MPG combined 104g/km CO2 and 0.01 NOx
Polo BlueMotion with A/C and Stick 70.6 MPG combined 104g/km CO2 and 0.227 NOx
That is for a much smaller and lighter vehicle, and the numbers are very different from what they represent in the article.

Re: so much misinformation in comments for Clean Diesel Cars Green than Hybrids - New Fuel Efficient

Because diesels operate at a higher temperature and compression, they have a greater theoretical thermal efficiency. However, as Bulldog points out, the difference is not enough to come up to hybrids.

Also, they are promising us clean diesel. But they also promised us that nuclear power would be too cheap to require an electric meter; that GMOs would free us from pesticide use, and that the war in Iraq would be over quickly and bring democracy to that country.

I do not believe for a minute that "clean" diesel will be anywhere near as clean as the Prius. Maybe a really small "clean" diesel will be cleaner than a Hummer.

Re: so much misinformation in comments for Clean Diesel Cars Green than Hybrids - New Fuel Efficient

daniel i agree. the chemical makeup differences between gas and diesel suggests that a diesel would have to get much higher mpg's to even equal Prius "cleanliness"

Re: so much misinformation in comments for Clean Diesel Cars Green than Hybrids - New Fuel Efficient

I like how they mention that they "didn't look at" smog emissions data

Based on 2007 UK data for Polo BT vs. Prius, CO2 is even, CO is 32% higher, and NOx is 2170% higher

Never mind that the Polo is considerably smaller and even slower than the Prius.

Rob

Re: so much misinformation in comments for Clean Diesel Cars Green than Hybrids - New Fuel Efficient

I agree, it is rather ignorant.

None of us drive in a bubble nor do we live in a bubble. Everything we do has an effect on something else. To not look at the smog emissions data is to completely ignore this basic fact of life. A vehicle may use very little fuel yet if the emissions are still high then the costs will be externalized and the community will pay the price of that inefficiency. The price can come in the form of health care, lower agricultural productivity, environmental degradation (that may or may not get cleaned up), and quality of life for humans (those suffering from the effects of these chemicals).

Re: so much misinformation in comments for Clean Diesel Cars Green than Hybrids - New Fuel Efficient

In truth a barrel of crude always gives x gallons of gasoline and y gallons of diesel, so each is just a byproduct of producing the other. However, it takes a lot MORE energy to produce gasoline than diesel overall because it is a much more pure/refined and complex fuel than diesel and it requires a large number of chemical additives to make it work. It takes much less energy to refine diesel from crude, as it is a very simple fuel with a quick and simple extraction procedure.

However, the biggest advantage of the diesel engine is not related to fossil-fuels but to farming. The best gasoline biofuel equivalent - ethanol - is hugely inefficient and wasteful to produce. Biodiesel on the other hand has a great energy balance and the potential to replace crude entirely once the algae cropping systems mature.

Re: so much misinformation in comments for Clean Diesel Cars Green than Hybrids - New Fuel Efficient

Hi Clett,

For present vehicle fleet, a point can be made that the best bio-fuel is not ethanol, but butanol. All the expensive issues with ethanol are eliminated with butanol. It gives 30 percent more energy per gallon. It gives 30 percent more energy yield per bushel of corn. It can be pipeline transported. It can be run at any fraction in gasoline. It is an oxygenate, and reduces HC emissions. Being a very mild solvent, it will maintain a clean engine and fuel system. It can be blended and burned with diesel as well. Check out www.butanol.com


Ethanol is the best fuel oxygenate additive (maximum oxygen for minimum additive volume) and race-car bio-fuel (very high octane) however. The original use of ethanol was as an oxygenate. It was never intended to be a fuel itself. This has just sorta happened with little thought put into it. Because the infrastructure for making ethanol was just there not making enough money.

Re: so much misinformation in comments for Clean Diesel Cars Green than Hybrids - New Fuel Efficient

Quite the opposite. Ethanol was the fuel of choice a century ago. Gas didn't emerge as the preference until decades later.

As for the thought, there is almost 20 recent years of work put into ethanol blends. E10 & E85 has quite a history here and now E20 is making progress. Effort to produce it using waste matter for both product source and processing heat continues.
.

Re: so much misinformation in comments for Clean Diesel Cars Green than Hybrids - New Fuel Efficient

That investment in ethanol may be hindering developement of other fuels. Butanol has the potential of being the superior choice; more energy and compatiable with existing fuel and transfer systems from the same raw materials and processing system as ethanol. But it doesn't have a CAFE loop hole, and the big money is behind ethanol.

Both require an energy intensive distillation though, which is why biodiesel has a greater net energy.

Re: so much misinformation in comments for Clean Diesel Cars Green than Hybrids - New Fuel Efficient

If one assumes a diesel engine to be using petro-diesel, then, most likely, the hybrid will come off cleaner with fewer emissions.

If the diesel engine is using bio-diesel, then all bets are off and I think there is a much closer match. I don't have the graphs to support that idea, but my partner who makes his living as a biodiesel educator, consultant and promoter, probably does.

Since biodiesel can be produced from waste agricultural products and used veggie oil, one could be getting double usage from a given bio source and that should be taken into consideration when estimating the CO2 footprint for its production.

Any ethical future for biofuels will have to come from non-food sources unless we want to live in a world where the rich drives cars on food that should be going to feed people.

Re: so much misinformation in comments for Clean Diesel Cars Green than Hybrids - New Fuel Efficient

A compact size car VW Polo vs med size Prius?

Did anyone factor in Toyota's compact size car Aygo 1.4L diesel?

http://www.easier.com/view/News/Motoring/Toyota/article-48913.html

Re: so much misinformation in comments for Clean Diesel Cars Green than Hybrids - New Fuel Efficient

Hi, cwerdna (& any of you who poo-poo'd the lack-of-reliability comment),

I can speak from experience about the lack of reliability of the VW diesel engine. First of all, understand that I'm NOT bashing diesel engine technology [I love the fact that diesels built from the ground up as diesels (NOT the Oldsmobile and VW conversions) are generally very durable and maintenance free for a long period of time and have excellent fuel efficiency].

My '78 VW Rabbit Diesel was a real fuel sipper (1978 EPA, City:40 MPG, Highway:53 MPG ; 1977 EPA, City:39 MPG, Highway:52 MPG) but also very zippy since it was a high revving engine for a diesel (governed at 4,750 RPM's). I installed an alternator-pulsed tach in it (since no electrical ignition system to tap into for a standard tach) and was able to keep my RPM's fairly low with the 5-speed transmission, yielding 58 to 62 MPG on highway trips. I loved the car, but the exhaust smell and the soot made my wife sick around it, so I used it for my work and my solo trips and used the other family car when we were together.

Maintenance was similar to my Prius : just oil/oil filter chgs and fuel filter and air filter chgs UNTIL I got my 1st cracked block (of 3 cracked blocks, ALL within the first 45,000 miles) on my first ever NEW car. One of the dealer's DIESEL techs told me that he saw a document at the VW diesel train'g facility in NJ that listed a huge batch of engine blocks that were poorly cast at one of VW's plants, and if my engine serial number(s) were on that list, it/they would be replaced for free. I asked the service manager [and later the roving factory service rep (who travels to all the different dealerships that have unusual or hard-to-solve problems)] about this document and they both denied that it existed. I told the tech what they said and he told me again that he saw it in NJ and that one came into my/his dealership and was filed in among the dealership's service bulletins. He told me they just didn't want VW to have to eat the cost and he was afraid to confront his boss and possibly lose his job by siding with me.

I should have had some clue to my impend'g upcoming troubles and sold the car before they bit me, because in talk'g to other VW Rabbit DIESEL owners, I found many who had developed blown head gaskets (some more than once) and many more who told me they were on their 2nd or 3rd engines (I just assumed they had extremely high miles on their cars). I should have asked more questions early on. Eventually I learned what some were speculating or were actually told. It seems that VW just took their 1.5 L Rabbit gas engine and bored it out ot 1.6 L (removing block material and weaken'g it somewhat), replaced the spark plugs with fuel injectors, replaced the carburetor with an injection pump, chg'd to longer pistons for higher compression (for self ignition of the diesel fuel) and VOILA!!--a diesel conversion.

Problem was, when you take an engine designed to withstand only the stresses of an 8 to 1 compression ratio (in the gas version) and now make it to run at a 24 to 1 compression ratio (required to auto-ignite the diesel fuel) and weaken the block (by boring the cylinders out larger) and NOT adding any extra head bolts to compensate for the tripled increase in compression stresses, you wind up with either blown head gaskets [because the tie-down points (head bolts) are so far apart] or the blocks cracked AT the head bolt locations (because all the increased stresses were concentrated at those few points). On one of my cracked blocks I had a whole corner of my block dangling on a head bolt (after it broke away) and spraying hot coolant all over the engine compartment. BOTH the gas and diesel versions of the Rabbit's engine only used 10 head bolts [and the same was true of the later Golf TDI (diesel)], but if you compared the 4-cylinder Peugeot gas versus diesel engines of the same time period, there was either 10 or 12 head bolts in the gas job but 23 head bolts in the diesel (and it was designed & built from the ground up as a diesel---NOT a conversion). I never bothered to learn about the differences between the Mercedes gas & diesel engines.

I had other issues with VW [such as NOT contact'g owners of prior model year diesels (prior to the "DON'T use ether/start'g fluid on your diesel engine" warn'g that was in later owner's manuals) & NOT providing stickers to that effect for inside the engine compartment or to insert in your early model owner's manuals], which caused me to wipe out my valve train & nick all my pistons when I used ether to try to start my engine on one extremely cold winter day. They said when I had it towed in that I didn't read the "NO ether" warn'g in my manual, so I deserved what I got. I handed them my manual & asked them to show me where that warn'g was, & when they couldn't find it in my '78 owner's manual, they just said it must not have gone in until the '79 or '80 manuals and "just because you don't have the specific warn'g in your manual doesn't mean it's O.K. to try something NOT specifically mentioned in the manual, but in all cases you MUST adhere to the manual".

Yet, when I picked up the repaired car & questioned the $4 chrg for a gallon of antifreeze (when the owner's manual specified "You MUST use phosphate-free antifreeze" which back in that time was hard to find/obtain and ran $16 a gallon in the dealer's parts dept), the same service dept told me "NOT to believe what's in the owner's manual & just use regular antifreeze". I found out that the phosphates in the regular antifreeze react with the different metals in the engine block, head, radiator, etc and eat up the $400 aluminum radiator (a way for the dealership to make more money on you later). I was fortunate to buy my radiator when they were running a 50% off tag sale for father's day and saved myself $200 (that's more than a $200 markup because they still sold it at a profit at only $200) and when I told the parts man about the condition of my original radiator, the 1st thing out of his mouth was "you tried to save yourself some money & didn't use the $16/gal phosphate-free stuff when you chgd your coolant, right?". Then when I told him his own service dept put the regular stuff in & told me NOT to pay any attention to that requirement in the manual, he got that "deer in the headlights" look.

I'm sorry I rambled on so long on this topic, but it just struck a nerve when some of you questioned the lack-of-reliability comment & I could provide personal experiences to support that comment. My experience with a poorly designed VW diesel was VERY costly---so costly that I had seriously considered removing the last diesel engine & replacing it with a gas engine, but that would require more than just the engine. I would also have to buy & install all the emissions stuff inder the hood that went along with a gas engine (& a catalytic converter too), so at 45,000 miles I just parked it & let it rust. Everything started happen'g just after the warranty expired & if I recall, they weren't very long in those days anyways & I don't think the lemon laws were around to help then either. Nobody was interested in buying my diesel VW with the reputation they were develop'g, so I called the auto junk yards & I had to pay to have it hauled away & scrapped. What a way for my 1st new car to live out its short life!

Ken (in Bolton,Ct)

Re: so much misinformation in comments for Clean Diesel Cars Green than Hybrids - New Fuel Efficient

biodiesel is carbon-neutral. so is veg oil.

i'm sure your partner knows all about emissions differences between b100 and dino diesel, all i know from reading is that veg oil emissions are for the most part similar to dino diesel depending on the type of oil. reductions in one of the types of gases, but i can't find which one.

Re: so much misinformation in comments for Clean Diesel Cars Green than Hybrids - New Fuel Efficient

That's not entirely correct. The particulates from fossil diesel are hugely toxic. Actual (transit) maintenance workplace comparisons between biodiesel burning engines and petro-diesel engines shows a significant reduction in particulates. One transit facility was able to eliminate the air scrubbers in their garages. Biodiesel is a natural solvent, so engines run much cleaner. Because of its solvent properties, older engines with rubber hoses need to be adapted to run on biodiesel.

Burning biodiesel itself is probably carbon neutral, but you need to consider the carbon generated in producing the source product. Some argue that the "carbon cost" of the production of biodiesel outweighs the alleged advantage, but I disagree. The sheer carbon cost of transporting crude oil halfway around the world trumps any carbon produced on the farm.

Re: so much misinformation in comments for Clean Diesel Cars Green than Hybrids - New Fuel Efficient

This statement would be completely correct if not for the cracking process. Because gasoline is a high-demand product, refineries use a cracking process whereby hydrocarbon molecules are broken into smaller fragments, then recombined into a more useful form; in this case gasoline. There is a cost associated with it, so there is a limit to how far a refinery will go with cracking, but they do make more gasoline than what naturally occurs in petroleum.

Another thing about diesel engines is that they can burn just about anything flammable that you can squirt through the injectors. Diesel himself made one that worked on coal dust, but injection proved to be unreliable.

I didn't notice anyone posting about the prospect of using a diesel hybrid. A clean burning diesel would work well to power a hybrid car, since the electric portion would ease starting problems and allow the engine to operate within a narrow band. If diesels prove to be good, I'm sure we will see hybrid versions.

Tom

Re: so much misinformation in comments for Clean Diesel Cars Green than Hybrids - New Fuel Efficient

That is a good post. Thought I let you know it was a good read, even though few comments have been made.