Sad to see that this side of the world is controlled by GREEDY petrol gangsters* while over in Europe the much more expensive diesel is sold more than gas. More than half of the place have diesel engined clean diesel's doing in excess of 60 - 70 mpg - and going very fast on the freeways.
I wish "whoever controls this stuff" in the USA would allow these small mechanical wonders over here but the excuse is always the same. Talk to any VW dealer - "the engines are not clean enough for the USA". Bull Ship I say.
Waiting to drive the new VW Beetle diesel as soon as they arrive in Naples. Can't wait.
Keep smiling
Peter Marsh
Naples
* If this offends anyone - I don't care.
On Jan 22, 2012, at 1:04 PM, Chris S. wrote:
> In real life the gain in mpg for diesels is more than 25%.
>
> http://www.greencarreports.com/news/1019256_volkswagen-jetta-tdi-much-more-mileage-than-epa-admits
>
> And yes, winter prices of diesel are obnoxious.
>
> And as for reliability, I put 200k miles on my Beetle TDI. I replaced the injection pump for $400 at 168k miles. Outside of regular maintenance and the injection pump, all mechanics were original. Nothing else failed. Clutch, alternator, A/C and so on were original. At 47mpg during my commute it was tough to sell it.
>
> But I get your point. Diesels will never catch on on the US. They have brainwashed us for decades and most folks don't bother to look beyond the easy-to-digest label.
>
> Chris.
>
> Wysłane z iPhone'a
>
> Dnia Jan 21, 2012 o godz. 15:29 Dennis Haynes <d23haynes57@HOTMAIL.COM> napisał(a):
>
>> -----Original Message-----
>> From: Dennis Haynes [mailto:d23haynes57@hotmail.com]
>> Sent: Wednesday, November 23, 2011 12:57 AM
>> To: 'Mike S'; vanagon@GERRY.VANAGON.COM
>> Subject: RE: Vanagon? Really? Gasoline vs. Diesel
>>
>> Over the years there are a number of folks that somehow get convinced that
>> Diesel is the way to go and consider ways to convert. There is always the
>> question of why more diesels are not available. This may be more of a Friday
>> topic but I'll try to shed some light. Of wonderful note we are starting to
>> see some interesting technologies for both gasoline and Diesel engines but I
>> see a number of forces that will keep Diesel use for small vehicles limited.
>>
>>
>> For one thing the new clean fuel requirements and other forces are making
>> Diesel fuel too expensive. Even home heating oil is going up. On this
>> current trip from New York to Florida I have witnessed as much as a $.80
>> price difference from regular unleaded to Diesel. That alone wipes out the
>> 25% fuel economy improvement if that's what you get. Many Diesel vehicles
>> 2007 and newer also require the use of a special Diesel Exhaust Fluid,
>> (DEF). This is a urea based fluid used to mix with the exhaust in the
>> catalytic converter to reduce the oxides of nitrogen (NOx) emissions. Due to
>> high compression ratios and the excess air, diesels make a lot of NOx. An
>> awful lot. This is a primary contributor to smog and why Diesel cars sales
>> were not allowed in many Northeast states from 2003 to 2006. I don't know
>> how much DEF is used per mile but I see the truckers by it in five gallon
>> pails.
>>
>> Another big issue is both the increased purchasing and operating costs.
>> Gasoline engine technology is now to the point that there is very little
>> scheduled maintenance and almost any engine out there now can go 150,000 to
>> 250,000 miles. Diesels have very expensive injection systems and all have
>> turbo chargers. The turbo alone can be a huge maintenance hit when it fails
>> and many will at around 100,000 miles or less. Often a turbo failure will be
>> the bearing assembly. This can allow engine oil to enter the intake track
>> and when the engine sucks it in the engine can go into a run away. No way to
>> shut it down until it blows. I have seen a number of Cat engines fail this
>> way. The new Diesel injection pumps and injectors have very tight tolerances
>> and any contamination will quickly destroy them. The final filters on many
>> of them filter to 2 micron.
>>
>> So why do Diesels get better fuel economy? There are three main advantages
>> to a Diesel. Diesel fuel has a higher BTU content than Gasoline, operates
>> at higher compression, and the biggie is the lack of a throttle. Why does
>> the throttle thing help economy? To begin with you do not have the vacuum or
>> pumping losses. The inlet is always wide open so each intake stroke takes in
>> as much air as can be sucked in or that the turbo can force in. With a gas
>> engine when you lift your foot the engine and the vehicle slows down. With a
>> Diesel the vehicle will only slow down if going uphill or going fast enough
>> for wind resistance to slow you down. No energy is used to suck the air fuel
>> mixture through a throttle plate. Now since an engine produces power by
>> heating-expanding gases, having the cylinders fully charged with air, turbo
>> pressurized air any fuel burn is going to produce a much greater pressure
>> change, (power) than a partially charged cylinder would as in a gas engine.
>> This really gives the Diesel an advantage at partial load, low speed
>> operations. To add further to control emissions, modern Diesel injectors do
>> not simply shoot fuel into the cylinder at the right time. They actually
>> inject in steps to what is known as wave shaping. They start with a small
>> shot to get a burn going, then go for a power shot and then an after burn to
>> clean up soot. Yes for each cylinder power stroke the injector can fire
>> three times are some variable amount during the full power stroke. This
>> makes for complicated injectors as they not only operate electrically but
>> the electric part operates a pilot or control valve in each cylinder and
>> then depending on the injector design either high pressure fuel or engine
>> oil actually hydraulically operates the injector pin. This is often known as
>> a Hydraulic Electric Unit Injector, (HEUI). On some engines these are
>> calibrated so tight then when replacing them the replacements get stamped
>> with trim numbers to reflect differences from the ideal standard. When
>> installed you need to go into the ECU and program the trim numbers for the
>> new injectors and the cylinders they were installed in.
>>
>> A Gasoline, (spark ignition) engine has to run with a controlled fuel-air
>> mixture. In order for the engine to run at a given RPM, it has to have a
>> certain volume of air and that volume has to have a matching, (14 to1)
>> amount of fuel go with. The Diesel does not need this. Note that in some
>> applications Diesels are also run with propane or natural gas.
>>
>> So where are we going with this. We are starting to see gasoline engines
>> that will be direct injection and at some point we will see them going to
>> compression ignition. The wave shaping technology described above will allow
>> gasoline to be burned at much wider mixture ranges. So for idle and low
>> speed we can use the spark ignition and normal mixture control for
>> smoothness and when under way go to compression ignition, maximum air
>> intake, and maximum power and efficiency. This along with Hybrid technology
>> is going to be the future for automobiles and light trucks. Diesels will
>> still have their place for industrial and large truck, locomotives,
>> generators etc. but the new stuff will be complicated and until these new
>> technologies get refined somewhat expensive to maintain.
>>
>> Dennis
>> -----Original Message-----
>> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
>> Mike S
>> Sent: Saturday, November 19, 2011 11:25 PM
>> To: vanagon@GERRY.VANAGON.COM
>> Subject: Re: Vanagon? Really?
>>
>> At 10:45 PM 11/19/2011, Dennis Haynes wrote...
>>> As Gasoline engines go to
>>> direct injection and dual mode, (spark ignition to compression
>>> ignition) the
>>> Diesel advantages will disappear.
>>
>> Compression ignition _is_ Diesel. It's not a matter of what fuel it uses.
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