Winter diesel

from Wikipedia, the free encyclopedia
After three days in the cold test, the starting of the engine is tested. (Automobile factory in Great Britain 1945)

Winter diesel is a diesel fuel with additives that reduce the flocculation of paraffins at lower temperatures. Without these additions paraffin form in the fuel lines crystals caused by blockage of the fuel filter prevent flowing through the diesel fuel from the tank to the engine. The cold filter plugging point (engl .: C old F ilter P lugging P oint, CFPP ) in which a test filter clogged under defined conditions is significantly reduced in the winter diesel over the summer diesel.

Another reason for normal diesel fuel to freeze is that it can absorb up to 8 percent water, which then freezes in winter. Many diesel cars are equipped with a filter pre- heater that ensures operation with winter diesel above the temperature value specified in the CFPP.

Winter diesel tends to have a lower cetane number than summer diesel, as winter fuel sometimes has to do without higher-boiling components due to the necessary low-temperature properties.

Commercial grades

Winter diesel

The filterability limit (usability) of the diesel fuel is regulated by the CFPP value depending on the season in EN 590 - the winter diesel already receives special additives in the refinery for the winter season from November 15 to February 28 and must have a CFPP value of −20 Reach ° C or lower. Many mineral oil companies typically lower the CFPP value to −22 ° C in the winter months, resistant to cold. In a transitional period, diesel fuel must work down to −10 ° C; in Germany this is required from the beginning of October to mid-November and from the beginning of March to mid-April.

The high-priced premium diesel fuel types offered by many mineral oil companies have a guaranteed CFPP value of −24 ° C or −40 ° C and a typical value of −28 to −38 ° C. In Austria, the ÖAMTC traffic club determined a resistance of no more than −27 ° C for all samples in a test that was not comparable to German conditions.

At the filling stations in Germany and Austria, only winter diesel is offered from November to spring, in Switzerland all year round. Therefore, no difference is normally noticeable to the consumer.

The European standard EN 590, which is valid throughout Europe, defines six classes of diesel fuels for moderate climates - these have replaced the older definition for winter diesel, such as in DIN standard DIN 51628. The cloud point is not specified in EN 590, in DIN 51603 for heating oil a cloud point below +1 ° C is required at CFPP −10 ° C. Available additives reach a CFPP of −20 ° C based on diesel fuel with a cloud point of −7 ° C. The test definition with its standardized laboratory conditions is criticized by the ADAC as too weak - in experimental tests with different types of diesel with different diesel engines in the cold chamber, no direct correlation between CFPP value and cold start capability could be observed.

Class a class B Class C Class D. Class E. Class F
CFPP value +5 ° C 0 ° C −5 ° C −10 ° C −15 ° C −20 ° C
Cloud point (not specified in EN 590)

Polar diesel

In some regions of Europe where even lower temperatures are to be expected (e.g. in Scandinavia ), polar diesel is also offered in addition to winter diesel . This is a diesel fuel that, with the help of other additives, can sometimes be used down to −40 ° C. The general delivery offer includes a specification with CFPP of −33 ° C as polar diesel .

EN 590 defines five classes of diesel fuels for arctic climates. Even if it is not required by law, manufacturers use these definitions for their premium diesel. A low cloud point in EN 590 ensures that paraffin particles are not precipitated on the bottom of the tank after a while , as the daytime temperatures can dissolve them. A kerosene-like fuel with a correspondingly low cetane number (in EN 590 at least 45 for polar diesel) would be necessary to achieve a resistance to cold beyond class 4 .

Class 0 class 1 2nd grade Class 3 Grade 4
CFPP value −20 ° C −26 ° C −32 ° C −38 ° C −44 ° C
Cloud point −10 ° C −16 ° C −22 ° C −28 ° C −34 ° C

Range of gas stations

The measurement methods for diesel fuels are defined in the EN 590 standard, which is standardized in all EU countries, Iceland, Norway and Switzerland. This standard was introduced in connection with the definition of emissions standards that provide for a reduction in sulfur levels for diesel. It contains the Cold Filter Plugging Point (CFPP) as a filter test. In the USA, the “Low Temperature Flow Test” (ASTM D4539) was also developed, a standardized method for determining the winter resistance of diesel with additives, which, however, is not binding for diesel fuels in the ASTM D 975 standard. Both the filter point by CFPP and LTFT are a few degrees above the solidification point ( pour point ), from which the diesel can not be pumped.

Germany

The times and minimum requirements are regulated in DIN EN 590. The self-defined requirements for premium diesel of the mineral oil companies partly contain CFPP values ​​that go beyond the requirements for winter diesel throughout the year. (OMV MaxxMotion CFPP −40 ° C, Aral / BP Ultimate Diesel CFPP −24 ° C / −30 ° C) Most petrol station chains guarantee that they will deliver winter diesel with CFPP −22 ° C.

designation CFPP value Period
Summer diesel 0 ° C April 15 - 30.09.
Transition period −10 ° C 01.10. - November 15
Winter diesel −20 ° C 11/16 - 28.02.
Transition period −10 ° C 01.03. - April 14th

Austria

The transition diesel in Austria guarantees usability down to −15 ° C. Premium diesels on offer from the mineral oil companies sometimes contain CFPP values ​​that exceed the requirements for winter diesel throughout the year. (OMV MaxxMotion CFPP −40 ° C, Aral / BP Ultimate Diesel CFPP −24 ° C / −30 ° C)

designation CFPP value Period
Winter diesel −20 ° C 01.10. - 28.02.
Transition period −15 ° C 01.03. - 31.03.

Switzerland

Although there is a distinction between summer and winter diesel in the SN EN 590 standard, an all-year-round diesel has become established in Switzerland - the winter diesel defined in the standard is offered all year round at petrol stations. This circumstance led to irritation when the Austrian mineral oil company OMV introduced a premium diesel under the trade name "Winter Diesel" at the end of 2010, which with a guaranteed CFPP value of −35 ° C corresponds to the quality described above as polar diesel. Other mineral oil companies also offer premium diesel whose CFPP values ​​are guaranteed to exceed the requirements for winter diesel throughout the year. (OMV MaxxMotion CFPP −40 ° C, Aral / BP Ultimate Diesel CFPP −24 ° C / −30 ° C, Agrola Diesel cleanline CFPP −30 ° C)

designation CFPP value Period
Year-round diesel −20 ° C all year round

Australia

The Australian standard for diesel vehicle AS 3570 specifies the limit values ​​for the cloud point individually for the twelve calendar months, each divided into twelve climatic areas in Australia. The values ​​given for the twelve climatic regions are between −3 ° C and 15 ° C. In Australia, the CFPP value is typically set at 2 ° C below the cloud point. The standard also names special areas in which particularly cold weather situations can occur (e.g. Australian Alps ).

Highest permitted cloud point (AS 3570-1998)
Jan Feb Mar Apr May - Jul Aug Sep Oct Nov Dec area
[° C]
15th 10 5 2 1 4th 7th 11 14th 15th AUC Australia - Central (NT / SA)
15th 15th 12 9 8th 10 14th 15th 15th 15th AUN Australia - North (WA / NT / QLD)
9 5 2 0 −1 10 14th 15th 15th 15th NSW New South Wales
15th 12 7th 4th 2 4th 7th 12 15th 15th QC Queensland - Central
15th 15th 11 7th 6th 8th 11 15th 15th 15th QCN Queensland - Central North
15th 15th 12 7th 7th 9 12 15th 15th 15th QFNE Queensland - North East
11 7th 3 0 −1 0 2 7th 9 13 QS Queensland - South
8th 6th 4th 2 1 2 4th 5 6th 9 SAS South Australia - South
3 1 −1 −2 −3 −3 −1 0 2 3 TAS Tasmania
9 6th 3 1 0 1 2 4th 6th 8th VIC Victoria
15th 15th 9 6th 5 7th 11 15th 15th 15th WAC Western Australia - Central
10 6th 4th 3 2 2 3 5 8th 10 WHAT Western Australia - South

Belgium

Belgium has adopted the European standard for diesel fuels in the national NBN EN 590. The winter diesel is specified by law as CFPP −15 ° C. The mineral oil company VanRaak also guarantees a CFPP of −20 ° C in the period from November 1st to February 28th and offers a transition diesel with CFPP of −11 ° C throughout October. A winter diesel with CFPP of −20 ° C will be offered at the “power” brand petrol stations from October 15 to March 15.

designation CFPP value Period EN 590
diesel d'hiver / winter diesel −15 ° C 01.11. - 28.02. Class E.

Denmark

In Denmark, the standard DS EN 590 applies. There are three periods with different CFPP for diesel fuels, each for winter (winter), autumn (Efterår) and summer (summer) - other values ​​given correspond to the actual analysis at Shell and Statoil in Denmark.

designation CFPP value Period Actual CFPP Actual cloud point
summer −10 ° C 04/01 - 30.09. −12 ° C 0 ° C
Efterår −15 ° C 01.10. - November 30th −18 ° C −7 ° C
Vinter −20 ° C 01.12. - 31.03. −24 ° C −10 ° C

Finland

The measurement regulations of EN 590 apply.

section CFPP value Period
Summer period −5 ° C 04/01 - 31.10.
Winter period −26 ° C 01.11. - 31.03.

France

In France, diesel fuels correspond to EN 590 - classes B, E and F, for summer diesel, winter diesel and onset of winter respectively.

designation CFPP value Period EN 590
diesel d'été 0 ° C 01.05. - 31.10. Class B
diesel d'hiver −15 ° C 01.11. - April 30th Class E.

Canada

Canada generally has an arctic climate. The Canadian General Standards Board publishes maps of common regional low temperatures so that gas station chains can adjust diesel fuel, which they do about ten times a year. This principle follows the US standard ASTM D 975, which also describes wintry diesel (see United States ). Measurements at the filling stations showed that diesel fuel has a pour point of -30 ° C, which is typical for polar diesel in the rest of the world.

Netherlands

The DIN standard applies in the Netherlands (see Winter Diesel Germany ). A separate standard has not been published, since deliveries to petrol stations often take place across borders (e.g. at Shell ).

Norway

Norway has adopted the European specification in classes in the NS-EN 590 standard. In the central winter period, Arctic winter diesel according to class 2 (Vinterdiesel Arctic grade 2) is offered. The periods shown can vary by ± 14 days depending on the region.

classification CFPP value Period
minimum −11 ° C 04/01 - 09/15
Winter diesel −24 ° C 16.09. - November 30th
Polar diesel −32 ° C 01.12. - 28.02.
Winter diesel −24 ° C 01.03. - 30.03.

Poland

Some petrol station chains have extended the statutory minimum periods by a few weeks. In particularly cold winter periods, a switch is made to polar diesel down to −32 ° C, in some regions even −40 ° C. Some mineral oil companies guarantee a lower filterability limit for their premium diesel (BP Ultimate Diesel CFPP −30 ° C all year round, Statoil DieselGold / SupraDiesel CFPP −40 ° C winter time)

section CFPP value Period
Transition period −10 ° C 01.10. - November 15
Winter time −20 ° C 11/16 - 28.02.
Transition period −10 ° C 01.03. - April 15

Russia

In Russia, GOST 305-82 regulates «Топливо дизельное. Технические условия »(Diesel fuel. Technical conditions) the properties of diesel. A distinction is made between three climatic qualities:

designation Density (max) Flash point (min) Pour point (max) Cetane number (min) Viscosity (20 ° C)
Летнее дизельное топливо (summer diesel) 860 kg / m³ 62 ° C −5 ° C 45 3.0-6.0 mm2 / s
Зимнее дизельное топливо (winter diesel) 840 kg / m³ 40 ° C −35 ° C 45 1.8-5.0 mm2 / s
Арктическое дизельное топливо (polar diesel) 830 kg / m³ 35 ° C −50 ° C 40 1.4-4.0 mm2 / s

Sweden

Sweden has basically adopted the European standard in SS-EN 590. However, the Swedish standard SS 155435 for diesel fuels (introduced in 1972 and last updated in 2016) will continue to be written, as the requirements for Ultra Low Sulfur Diesel go beyond the European values. Due to different taxation, only diesel according to the extended Swedish standard is offered at petrol stations in Sweden.

The supply by the state-owned Circle-K only knows a year-round diesel with a CFFP of -32 ° C. The OKQ8 petrol station chain, on the other hand, distinguishes between two areas all year round, in central Sweden limited to the Dalälven river to about 60 ° north latitude.

Same name CFPP value Period
Söder om Dalälven (southern diesel) −24 / −26 ° C all year round
Norr om Dalälven (Northern Diesel) −32 / −35 ° C all year round

Spain

The measurement regulations of EN 590 apply.

section CFPP value Period
Summer period 0 ° C 04/01 - 30.09.
Winter period −10 ° C 01.10. - 31.03.

Czech Republic

The times and requirements of Czech winter diesel (směsné motorové nafty) are regulated in ČSN EN 590. The qualities for mild climates are divided into classes A to F, the qualities for arctic climates are divided into classes 0 to 4. The temporally prescribed varieties correspond to the names Třída B, Třída D and Třída F (for the actual winter diesel). The diesels offered according to Třída 2 designate the polar diesel with a minimum usability down to −32 ° C (e.g. in ski areas).

designation CFPP value Period
Třída B 0 ° C April 15 - September 30.
Třída D −10 ° C 01.10. - November 15
Třída F −20 ° C 11/16 - 01.03.
Třída D −10 ° C 01.03. - April 14th

United Kingdom

In the UK, diesel is divided into winter fuel and summer fuel, according to BS EN 590 / BS EN14214 ( biodiesel ). The same values ​​apply to Ireland in IS EN14214. The delivery of winter diesel starts in November and ends in March.

designation CFPP value Period Cloud point
Summer Fuel −5 ° C 16.03. - November 15 3 ° C
Winter Fuel −15 ° C 11/16 - 15.03. −5 ° C

United States

In the USA, there are no state regulations regarding a specific period in which winter diesel must be offered, and the ASTM D 975 standard has no specific test value for the low-temperature properties of diesel fuels. Instead, the standard contains a regulation to measure the cloud point of the fuel and to ensure that this is not more than 6 ° C above the tenth percentile of the temperature minimum for the calendar month of the respective environment. The tenth percentile ( decile ) is calculated from the three coldest days out of 30 days of a month. The ASTM-D-975 standard contains a set of maps showing the tenth percentile to be expected for each month for each state.

In accordance with this guideline, suitable winter diesel is offered at filling stations - the low-temperature properties can be achieved in two ways

  • winter blend ("winter blend") - the petrol station has already added No. 1 kerosene to match the No. 2 diesel.
  • winterized diesel ("winterized diesel") - additives were added to the No. 2 diesel according to the temperature.

Since the treatment with additives is cheaper (1: 40000) than the mixture with kerosene, the winter diesel offered is mostly a winter-proof diesel. In cold regions there is No. 1 kerosene at the same pump, which gives the driver the opportunity to decide on a winter mixture himself.

Diesel mixture

Flow improvers

As an alternative, it is sometimes recommended that you buy the appropriate additives from a car accessory store and mix them yourself. These flow improvers are added to the diesel fuel in the tank. However, these additives can only be optimally mixed with the diesel at a fuel temperature of +20 ° C. If the fuel in the tank is colder, optimal mixing cannot take place and the additives cannot be effective.

Mineral oil companies and car manufacturers warn against adding flow improvers to the range of premium diesel or winter diesel (also types of the transition period) - the mixture of the additives already present in the fuel and the additives of the flow improver can worsen the properties, and instead of a better CFPP, the opposite effect can even occur to adjust.

Regular gasoline admixture

Up until the early 1990s, some operating instructions recommended adding up to 20% regular gasoline to the diesel oil, albeit with restrictions in terms of the economy and running behavior of the diesel engine. Today, this is mostly only possible with old diesel engines with pre- injection or swirl chamber injection and a relatively simple in- line injection pump as well as purely mechanical distributor injection pumps , even if these are lubricated by the fuel.

Adding gasoline to diesel drastically lowers the flash point of diesel fuel. This leads to an increased risk of explosion and should therefore not be carried out for safety reasons. More details are in the manual of the car. Vehicles with common rail - or pump nozzle - direct (since about 2000 in the market), the addition tolerated gasoline generally not because the lubricating film which is produced by the self-lubricating effect of the diesel fuel into the pump, is washed off by gasoline, which the Pumps damaged immediately. The engine must not be started even after accidentally using the wrong fuel.

Kerosene

In the US, middle distillate fuels are sold in classes - the first fraction “No. 1 fuel "corresponds to petroleum / kerosene , the second fraction" No. 2 fuel “the truck diesel for road traffic, the middle fractions are not in use, the fifth fraction is common as marine diesel oil and the bottom sixth fraction is rarely used as heavy fuel oil . In the petrol station network, it is common to use “No. 1 "and" No. Offering 2 “diesel (according to ASTM D975 specification) and leaving it up to the driver to choose the mixing ratio in which to fill up. The own mix is ​​advantageous in view of the long distances of many truck transports and rapid weather changes deep into the continent ( blizzards ), so that a general definition of a trade variety is often not sufficient. The “No. 1 “diesel has a natural CFFP of -40 ° C and it is generally advisable to calculate an extended resistance to cold of 5 degrees for every 10% additional No. 1 diesel. The widespread use of No. 1 diesel has led to the fact that some delivery vehicles based on diesel engines have to be refueled with the fuel.

The use of up to 25% petroleum in the tank to improve the low-temperature properties was also common in Europe for a long time, but has been replaced by the general availability of winter diesel with special additives. The “No. 1 fuel "is more expensive than" No. 2 fuel ", so that the winterized diesel is also used regionally - however, the definition of the minimum conditions for winter diesel is a matter for the states and in many states is left entirely to the petrol station chains. While the uncertainty of the winter hardiness of the commercial varieties tends to be for “No. 1 fuel "speaks, modern turbo engines with direct injection in particular do not achieve their actual performance (increased consumption) by using the" No. 1 fuels ". Some European car manufacturers are prohibiting the use of the “No. 1 fuels “completely. This follows reasons similar to the refusal to add gasoline to diesel for modern direct injection engines - “No. 1 ”petroleum is in the boiling fraction between gasoline and“ No. 2 “diesel.

activities

Warm up

Once the filter system and / or the lines and the tank have become too long , i. H. clogged by flocculated paraffin of the diesel fuel, external heating of the pump (fuel tank), the filter and the lines to around 20 ° C and adding flow improvers helps. The warm-up can e.g. B. by hot water, hot air, rheumatism blanket , warming up in a heated garage or in a painting room. Heating with an open flame should be avoided as this can lead to fire or explosion.

Fuel preheating

Automobiles can be structurally adapted for operation at low temperatures. Models for areas with arctic temperatures are supplied with fuel preheating as standard. Since the flakes in the fouled diesel first clog the fuel filter, the simplest option is to electrically heat the fuel filter - in this way, summer diesel can be used to run down to −7 ° C to −20 ° C.

Some diesel vehicles are also delivered in Central Europe with a filter preheating system. The driveability of the winter diesel improves beyond the CFPP value - for the VW TDI, winter diesel with CFPP -15 ° C is operationally safe thanks to the standard fuel preheating down to -24 ° C. However, after a period of idle time, the increasingly precipitated paraffin particles can make the cold start more difficult. With the argument of climate change, car manufacturers have also begun to do without filter preheating systems.

See also

Individual evidence

  1. a b ADAC: ADAC tests actual cold suitability of winter diesel: You cannot always rely on quality ( memento from April 12, 2013 in the web archive archive.today ).
  2. MaxxMotion OMV Premium Diesel
  3. Test of the temperature resistance of winter diesel ( Memento from May 16, 2006 in the Internet Archive )
  4. ↑ You cannot rely on the norm . ADAC blog on all tests from technology and mobility. January 29, 2013. Archived from the original on September 23, 2013. Retrieved on October 23, 2013.
  5. Tamoil Polar Diesel ( Memento from January 16, 2013 in the web archive archive.today ).
  6. ASTM: D4539 - 10 Standard Test Method for Filterability of Diesel Fuels by Low Temperature Flow Test (LTFT)
  7. a b c OMV winter diesel . omv.de. Retrieved on January 17, 2017: "OMV MaxxMotion Performance Diesel [...] has [...] winter protection down to -40 ° C [...] according to DIN EN 590"
  8. a b c d DEFENSE · LOGISTICS BASE OF THE ARMY: Technical data sheet Page no longer available , search in web archives: Diesel fuel  ( page no longer available , search in web archivesInfo: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (PDF; 10 kB), May 31, 2005.@1@ 2Template: Dead Link / www.lba.admin.ch@1@ 2Template: Dead Link / www.lba.admin.ch  
  9. a b c Aral Diesel in winter . Archived from the original on October 24, 2012. Retrieved on February 2, 2012: “[…] allows engine operation at very high and low - guaranteed to at least −24 ° C - ambient temperatures. The characteristic value for fuel filterability is typically significantly lower, down to below −30 ° C. "
  10. ^ ÖAMTC: Lexicon entry Winterdiesel
  11. shell.ch: Winterdiesel - Switzerland ( Memento from September 10, 2012 in the web archive archive.today )
  12. bp.com: Technical product data sheet BP Citydiesel (PDF; 45 kB), accessed on June 7, 2013.
  13. Confusion at the gas station - what is "winter diesel"? . n-tv. October 22, 2010. Retrieved February 2, 2012.
  14. Infos sur les produits - Diesel cleanline . Retrieved February 2, 2012.
  15. a b Setting National Fuel Quality Standards - Discussion Paper on Operability Fuel Parameters (Petrol and Diesel) ( English , PDF; 1.3 MB) Department of Industry, Science and Resources. section 7.6.1.1. The Australian situation. August 2001. Retrieved February 4, 2012.
  16. Van Raak: Trotseert winter diesel de winter wel? ( Memento from January 15, 2013 in the web archive archive.today )
  17. Van Raak: Comment lutter contrer l'hiver? ( Memento from January 15, 2013 in the web archive archive.today ) (French, accessed June 7, 2013).
  18. Poweroil: Diesel ( Memento from March 5, 2016 in the Internet Archive )
  19. DS / EN 590: 2009
  20. a b c Fyld en reaktor spillet ( Danish ) Haldor Topsøe. Retrieved February 3, 2012.
  21. Statoil Eurodiesel 10 (PDF; 59 kB) January 23, 2008. Accessed February 3, 2012.
  22. Shell Diesel Extra B7 (PDF; 56 kB) May 2011. Archived from the original on March 10, 2016. Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved February 3, 2012. @1@ 2Template: Webachiv / IABot / www.dlg.dk
  23. Petroleum Refining: Crude oil, petroleum products, process flowsheets by Jean-Pierre Wauquier, pages 215 and 216
  24. This Fuel Oil (Canada) . Retrieved July 1, 2018.
  25. a b Produktbeskrivelse - Diesel B7 ( Norwegian ) Unox filling stations. August 8, 2011. Archived from the original on April 13, 2013. Retrieved on February 15, 2013.
  26. auto-motor-i-sport.pl: Paliwa zimowe - norma na mróz ( Memento from February 15, 2012 in the Internet Archive )
  27. bp.com: Zimowy olej napedowy BP Ultimate - Często zadawane pytania (PDF; 79 kB)
  28. statoil.pl: Osoby prywatne
  29. Automotive fuels - Diesel fuel oil of environmental class 1 and 2 for high-speed diesel engines - Requirements and test methods . Swedish Standards Institute. Archived from the original on January 18, 2017. Retrieved January 18, 2017.
  30. a b miles diesel . Circle K. Archived from the original on January 18, 2017. Retrieved January 18, 2017: "Uppfyller standard SS 15 54 35 och SS-EN 590 och är fullt blandbar med likvärdiga dieselkvaliteter."
  31. OKQ8 Diesel Miljöklass 1 . OKQ8. Archived from the original on January 18, 2017. Retrieved January 18, 2017.
  32. ceproas.cz: Nafta motorová ( Memento of February 29, 2012 in the Internet Archive )
  33. a b mabanaft.com: Diesel product specification ( Memento from March 9, 2014 in the Internet Archive ) (PDF; 83 kB)
  34. tankservices.co.uk: Harlequin 5000BFS / A Bunded BioFuel Station ( Memento from May 1, 2013 in the Internet Archive )
  35. theaa.com: Driving to Europe in winter
  36. iastate.edu: Digression on Diesel Fuel Properties ( Memento of 7 April 2009 at the Internet Archive ).
  37. dodgeram.org: Diesel Fuel Characteristics and use : We add 1.25 gallons of Paraflow 527 per 1000bbls of each receipt.
  38. a b auto.at: Stay away from flow improvers in diesel
  39. die-auto-experten.de: Winter diesel from the gas station does not need a flow improver
  40. a b c Operating manual Golf 4 TDI, edition 2001, Volkswagen AG, section "Winter operation", quote: The vehicle is equipped with a filter preheating system. When using winter diesel, which is cold-resistant down to -15 ° C, the fuel system is operationally reliable down to about -24 ° C. [...] Fuel additives (flow improvers), gasoline and similar agents must not be mixed with diesel fuel.
  41. a b Incorrectly fueled - what to do? ADAC , archived from the original on July 26, 2010 ; accessed on December 22, 2009 : "This is not the case with common rail and pump-nozzle engines (on the market since around 2000): the engine must never be started [...] [otherwise] the entire injection system including the high-pressure pump, Injectors, fuel lines and tank may be required. […] There is a widespread misconception that a little gasoline in diesel does not do any harm and can even be used as a flow improver in winter. This no longer applies today. "
  42. ASTM: D975 - 13 Standard Specification for Diesel Fuel Oils
  43. "How to Blend No. 1 Diesel With Diesel Fuel for Cold Weather "
  44. Combi valve in the Polo Fox (PDF; 1.5 MB).
  45. TDI FAQ .
  46. Diesel through the winter (ÖAMTC Auto Touring, edition 12/2012, page 18f), quote: "In many places they (filter preheating systems) have been rationalized out of cars with the argument of climate change."