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Mazda 6 - Biodiesel Question - Med

HI,

I have a very simple (i hope) question that i need to be cleared up for future references.

If a car should not be filled up with anymore than 5% or even 7% biodiesel content, what would happen to the car if 30% was used.

Would there be;

a) an immediate sign of damage to the car just like if it were filled up with Petrol?;
b)immediate damage to the DPF or will it damage over a long time?;
c) greater possibilites that the oil levels can rise due to the DPF not being able to regenerate because of the amount of biodiesel content?;
d) a warning on the car whereas when the DPF needs to regenerate, it'll inject this so called 30% biodiesel into it to combust, burning the soot off given that this wouldn't happen, the DPF would fail to regenerate. (Obvious answer but needs to be asked)

For the finale:
Could putting a higher content of biodiesel in your car than the manufacturer recommends cause the car to run-away on its own?

Many thanks in advance.

Mazda 6 - Biodiesel Question - Collos25

I assume you made homemade diesel modern engines to not like high levels of vegetable oil ,the answer to your last part is No more likely to stop it .

Having run a Peugeot 405 estate on chip oil for many years been handed round the family its probably bake bean cans now but it ran well no smoke always started but this was a very uncomplicated 1,9 engine.

Mazda 6 - Biodiesel Question - gordonbennet

Don't Mazda 6's struggle to regenerate with real fuel let alone mix'n'match..

I wouldn't experiment with fuels on a modern Diesel and a Mazda 6 would be the very last vehicle i would try.

Mazda 6 - Biodiesel Question - slkfanboy

I think the DPF would clogg up as the regen would not work properly as the heat properties bioD are lower. So step one would be have the DPF removed. In winter the BioD would be more viscous and therefore the fuel will likely fail. Changing the fuel filter more often will also be required.

The big issue is with the type of engine in combination with fuel quality. BioD is not produced to the high ISO standards that like you would get from a petrol station. The fuel is further quite stress and so poor quality fuel could destroy the engine.

Mazda 6 - Biodiesel Question - xtrailman

I thought the problem would be the FUEL filter blocking up?

http://www.fleetnews.co.uk/news/2013/12/13/diesel-biofuel-content-suspected-cause-of-unexpected-winter-breakdowns/49096/

Edited by xtrailman on 19/12/2013 at 20:59

Mazda 6 - Biodiesel Question - Collos25

I think the DPF would clogg up as the regen would not work properly as the heat properties bioD are lower. So step one would be have the DPF removed. In winter the BioD would be more viscous and therefore the fuel will likely fail. Changing the fuel filter more often will also be required.

The big issue is with the type of engine in combination with fuel quality. BioD is not produced to the high ISO standards that like you would get from a petrol station. The fuel is further quite stress and so poor quality fuel could destroy the engine.

Its illegal to remove the DPF.

Mazda 6 - Biodiesel Question - edlithgow

It sounds to me as if the OP might be confusing biodiesel with straight vegetable oil.

In particular, the "running away" ref sounds like straight vegetable oil, which can cause piston rings to coke up and stick. This in turn allows sump oil to leak past the rings, and the engine starts to run (away) on its own sump oil, not stopping until something breaks, (which might not take very long) unless you can shut off its air supply and suffocate it. Shouldn't happen on biodiesel, though I can't say its impossible.

SVO can also cause your lube oil to gel (due to contamination by leaked fuel), and it can cause the early demise of turbos on otherwise suitable engines, due to chunks of coke hitting the turbine blades.

Commercially produced biodiesel should be OK, (check the specs with the producer) but if the manufacturer of your apparently rather modern / fussy / fragile car says don't use it, you'd probably be unwise to argue with them.

Here in Taiwan I understand all available diesel fuel has contained some biodiesel for the past few years (I think about 5%, but AFAIK the proportion is not fixed by the govt).

Havn't heard of any problems attributed to it yet, but the diesel car fleet is rather small here.

Mazda 6 - Biodiesel Question - Collos25

Here in Taiwan I understand all available diesel fuel has contained some biodiesel for the past few years (I think about 5%, but AFAIK the proportion is not fixed by the govt).

So it has in the EU any more and the system on a new engines will not likewith the possibility of causing thousands of pounds worth of damage it does not matter of its Bio factory made or Bio home made.

Mazda 6 - Biodiesel Question - slkfanboy

EU diesel has 5% biodiesel. Biodiesel is cleaned Veg oil (basically). The quality issue comes in that the Drain cleaner used must be removed from the Biodiesel prior to use, so depending on how well this is done determins the quality of the Biodiesel. So if large amounts of cleaner remain in the fuel it will damage your engine.

A max. mix of the 30% seams to be advised and none in very cold weather

Mazda 6 - Biodiesel Question - Collos25

EU diesel has 5% biodiesel. Biodiesel is cleaned Veg oil (basically). The quality issue comes in that the Drain cleaner used must be removed from the Biodiesel prior to use, so depending on how well this is done determins the quality of the Biodiesel. So if large amounts of cleaner remain in the fuel it will damage your engine.

A max. mix of the 30% seams to be advised and none in very cold weather

Bio diesel in Europe is rape seed oil,if you put a mixture which includes 30%bio diesel in a Euro 4 or 5 engine it will last a very short time before large amounts of money are required to put the engine back in a situation where it will run.

Mazda 6 - Biodiesel Question - edlithgow

EU diesel has 5% biodiesel. Biodiesel is cleaned Veg oil (basically). The quality issue comes in that the Drain cleaner used must be removed from the Biodiesel prior to use, so depending on how well this is done determins the quality of the Biodiesel. So if large amounts of cleaner remain in the fuel it will damage your engine.

A max. mix of the 30% seams to be advised and none in very cold weather

Bio diesel in Europe is rape seed oil,

No it isn't. It is made from rapeseed oil. BIG DIFFERENCE.

Paper isn't wood, steel isn't iron ore, polythene isn't natural gas, cement isn't limestone.

Mazda 6 - Biodiesel Question - xtrailman

I think we knew that.

Mazda 6 - Biodiesel Question - edlithgow

Yeh, sorry. I had a "This is important, someone is WRONG om the Internet" moment.

Mazda 6 - Biodiesel Question - edlithgow

.

So it has in the EU any more and the system on a new engines will not likewith the possibility of causing thousands of pounds worth of damage it does not matter of its Bio factory made or Bio home made.

Apparently it does according to Mercedes.

http://www.mbusa.com/vcm/MB/DigitalAssets/pdfmb/serviceandparts/biodiesel_Brochure5.pdf

"Home Brewed versus Commercially Produced Biodiesel

“Fuels which do not meet the ASTM specifications are NOT approved by Mercedes Benz and the Mercedes-Benz Limited Warranty does not cover damages caused by the use of fuels that do not meet Mercedes-Benz approved fuel standards !”

Volkswagen similarly only approve the use of fuel meeting their specifications.

Mazda 6 - Biodiesel Question - Collos25

Exactly approved fuels are sold at pumps with 5% bio diesel approved by all car manufacturers not just Mercedes.

I think you read and do not want to hear what you do not like you obviously have some sort of dispute and are now clutching at straws.

Edited by Collos25 on 22/12/2013 at 17:39

Mazda 6 - Biodiesel Question - edlithgow

I did a bit of reading, which I suppose I should have done before I first posted.

It appears the issues with biodiesel mostly relate to some of the filter regeneration systems, which have a second post-combustion fuel injection into the cylinder. This fuel is vaporized and is then burned in the exhaust filter, to de-carbonize it.

Bio-diesel is less volatile, so it doesn’t vaporize as well, and can increase fuel dilution of the lubricating oil.

http://savebiodiesel.com/chevron_dpf.pdf

Due to its polarity, there also seems to be the possibility that it will be incompatible with some of the polar additives in engine oil, leading to increased engine wear. I didn’t find any reports of in-service failures, so it seems to be a current theoretical/experimental concern rather than an established fact)

http://www1.eere.energy.gov/vehiclesandfuels/pdfs/deer_2007/session5/deer07_sappok.pdf

Biodiesel (unlike vegetable oil) is chemically quite stable, so it shouldn’t gel the oil or stick the rings to the extent that SVO can, which can cause catastrophic engine failure.

Another issue is that most commercial biodiesel contains up to about 20 percent methanol/ethanol (Note: This isn’t “drain cleaner”) which can trigger false "water in fuel" warnings displayed by the engine management system, which misreads the alcohol as excessive oxygen and often sends a "check engine" warning along with the "water in fuel" warning.

OTOH, there is some experimental evidence, (promoted, naturally by the biodiesel lobby, but apparently from independent sources) that biodiesel soot can be more easily oxidized in the filter, and so can reduce its effective operating temperature. http://savebiodiesel.com/40015.pdf.

Reported effects of biodiesel on various catalyst and filter systems were mostly negligible or slightly positive. http://savebiodiesel.com/42928.pdf

The OP is apparently well aware of these issues, and probably is NOT confusing SVO with biodiesel. (I apologise for that assumption).

I still think he’s wrong in saying:-

(a)“the oil levels can rise due to the DPF not being able to regenerate” The oil levels can rise due to dilution with the unburned fuel introduced by the DPF regeneration system, and can rise whether the DPF regenerates or not.

(b) “given that this wouldn't happen, the DPF would fail to regenerate. (Obvious answer but needs to be asked)” I don’t think its an obvious answer. I think (from the little reading I’ve done) that its unclear whether biodiesel would interfere with regeneration, BUT it seems that it may increase ash deposition and so reduce the life of the catalyst.

( C ) “I have a very simple (i hope) question.” No you don’t. You have a series of rather complex, controversial questions that (so far) no one has been able to answer, and which are currently topics of active research.

Faced with that uncertainty, you’d better do whatever the manufacturer tells you. They are probably hedging their bets as well.

This site gives current manufacturers recommendations for the US market. They seem to range from B5 (the norm) to B20

http://www.biodieselfoundation.org/docs/vehicles/2013-diesel-vehicle-list.pdf?sfvrsn=2

One detail caught my eye.

2014 Audi Q5 TDI: Approved for B5 Biodiesel Blends (up to B20 in Illinois)

Why would it be different in Illinois? Better fuel? Independent testing ?? Bean farmer lobby???

Like I said, this seems to be in a state of flux, so you’d better be cautious.

Mazda 6 - Biodiesel Question - dieselnut

I remember the OP's previous threads about the problems he had with his Mazda 6.

http://www.honestjohn.co.uk/forum/post/index.htm?t=77225

I think you were in dispute (to put it mildly) with Mazda & were taking them to court. Was this resolved, or are your current questions related to the ongoing dispute?

Mazda 6 - Biodiesel Question - edlithgow

I looked at that other thread, a long read, and rather disturbing if one had, or was planning, to buy a new diesel car.

If I understood it correctly, the fault was a rather sudden over-fuelling, leading to very rapid (within a week?) oil dilution by diesel, and a partial run away (it could still be switched off) of the engine.

From my reading, I think its rather unlikely that was caused by using biodiesel. (SVO might be another matter), but of course I can't be certain of that. I have no experience of DPF equipped cars, (and I don't want any) so I'm certainly not an expert.

Audi are experts, or at least they probably have more expertise than anyone else in this context. I'd bet they think its rather unlikely that this fault was caused by using biodiesel too, and I'd bet they can't be certain either. This probably doesn't matter.

What probably matters is that they have covered thier corporate ass.

IF more than the recommended proportion of approved biodiesel was used, and IF they can prove it, then I'd expect that any engine warranty offered would be void, irrespective of the cause of the fault.

Mazda 6 - Biodiesel Question - edlithgow

For "Audi" above read "Mazda" . Sorry

 

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