Fueling question

FormerOwner

Veteran Member
Joined
Apr 16, 2006
Location
Alabama
TDI
2013 Passat TDI SE 6spd; Former Owner 02 MkIV wagon
Ok TDI'ers... put your biases aside and answer this question...

Why can't we fuel our Passats with a concentration of, say... >10% Biodiesel?

What are the effects of running biofuels >10% in this engine?

I'm seeing a growing number of fuel stations with their pumps being labeled as including concentrations of B5-B20 into their D2 tanks.

Thanks in advance for your input. Remember, please keep your biases aside; I'm trying to understand why biofuels aren't too welcome in our setup.
 

40X40

Experienced
Joined
Feb 12, 2006
Location
Kansas City area, MO
TDI
2013 Passat SEL Premium
Ok TDI'ers... put your biases aside and answer this question...

Why can't we fuel our Passats with a concentration of, say... >10% Biodiesel?

What are the effects of running biofuels >10% in this engine?

I'm seeing a growing number of fuel stations with their pumps being labeled as including concentrations of B5-B20 into their D2 tanks.

Thanks in advance for your input. Remember, please keep your biases aside; I'm trying to understand why biofuels aren't too welcome in our setup.
Well, Your bias is surely shining bright! :D

Since Illinois officially pumps up to B-20 then anyone in the USA (mainland, I suppose?) can also run UP TO B-20 (ATSM specs, of course) because you COULD have driven through Illinois and have purchased fuel there....
It might take a letter from a lawyer it they balk at a related warranty repair though.

As far as WHY we can't run higher concentrations, you will have to ask VW. ;)



Bill
 

30_Yr_Dsl_Veteran

banned Ric Woodruff alias account and troll
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Lake Placid, FL
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2009 Jetta
It is merely a legal "out" for them, cooked up by their lawyers. There is no technical reason you cannot.

Just like our Owner's Manual for our '98 Jetta TDI says "for technical reasons, you cannot tow with this vehicle". Yet, my son recently towed a U-Haul trailer with his motorcycle and a bunch of other stuff inside from Orlando to LA, and the car was 16 years old & had 224K miles on it when he left, yet not a single bad thing happened!!!
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
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Location
South of Boston
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'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
Because of the mandate to run higher than 5% bio in Illinois, VW has allowed Illinois owners to run up to B20 without voiding the warranty. They caveats are watching oil level to make sure it doesn't rise from bio migrating in to the crankcase, and (I think) a shorter oil change interval. With those in mind I bet it would also work outside the state of Illinois.

But if it were me, I'd stick with B5 or less. I don't see any upside to running more unless you're forced to.
 

30_Yr_Dsl_Veteran

banned Ric Woodruff alias account and troll
Joined
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Location
Lake Placid, FL
TDI
2009 Jetta
Because of the mandate to run higher than 5% bio in Illinois, VW has allowed Illinois owners to run up to B20 without voiding the warranty. They caveats are watching oil level to make sure it doesn't rise from bio migrating in to the crankcase, and (I think) a shorter oil change interval. With those in mind I bet it would also work outside the state of Illinois.

But if it were me, I'd stick with B5 or less. I don't see any upside to running more unless you're forced to.
That is a bunch of bull crap! As if biodiesel would be "migrating in to the crankcase" any more than regular diesel.

I would use any kind of biodiesel myself; B5, B10, B15, B20, B50, B100. Biodiesel is fully compatible with regular diesel - period. :cool:
 

kydsid

Veteran Member
Joined
Apr 18, 2012
Location
Texas
TDI
2012 Passat
Other than checking the oil there isn't any mechanical reason up to 20% bio in a CR diesel afaik. Above that the injector pressures and temperatures a CR diesel sees may lead to breakdown of the bio and varnishing of the injectors. Where is that limit? I don't really know other than to say most other CR bio limits are around 20%. I'd guess that even 20% is assuming some margin of error.

Is there something more specific to a Passat? Not that I know of. I don't worry about any bio concentration myself I just fuel up. I personally think vw's bio limit is too low. It is the lowest out there for any CR diesel I know of.
 
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FormerOwner

Veteran Member
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Alabama
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2013 Passat TDI SE 6spd; Former Owner 02 MkIV wagon
Bill, I'm not biased, merely curious. I could care less about which fuel is better for me or for the planet. I simply don't want to deal with any problems in the future with the push for alternative fuels.
 

Tdijarhead

Top Post Dawg
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Lawrenceville PA
TDI
2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Wife’s car, 2005 Golf TDI Mine, all 5 spds
Bill, I'm not biased, merely curious. I could care less about which fuel is better for me or for the planet. I simply don't want to deal with any problems in the future with the push for alternative fuels.

I have to agree these engines are designed for and run best on diesel. I know that they were originally built for farmers growing their own fuel. However diesel was in those days so cheap why bother. As a result modern diesels are made to run on plain old diesel, and not necessarily something grown on the back 40 or cultivated in an over ripe pond. I'm all for an alternative that might be cleaner and cheaper, and doesn't ruin my engine or shorten its lifespan. I just haven't seen anything that fits that description yet. Back in the late 1800's whale oil was used to light our homes, a whale was hunted just for its oil and the carcas was left in the ocean. A capitalist by the name of JP Morgan decided to refine kerosene and he did it so cheaply that he could sell it for less than whale oil. What do you suppose people bought. Yup kerosene, Morgan became rich and saved the whale for future generations. Come up with a "kerosene" alternative fuel and you will become rich and save the planet.
 

jrm

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Oregon
TDI
2013 Passat SE with nav (totaled)
I watched someone in a 11' Jetta pull up to the B99 pump the other day, clueless and pretty much told me I am a hater of the world for telling him his DPF couldn't handle it.
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
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I watched someone in a 11' Jetta pull up to the B99 pump the other day, clueless and pretty much told me I am a hater of the world for telling him his DPF couldn't handle it.
This is why I'd be VERY reluctant to buy a used common rail TDI.
 

Rico567

Top Post Dawg
Joined
Jun 13, 2003
Location
Central IL
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2013 Passat TDI SEL Premium (Turned in 7/7/18)
Ok TDI'ers... put your biases aside and answer this question...<snip> Remember, please keep your biases aside; I'm trying to understand why biofuels aren't too welcome in our setup.
I think I might have a pertinent answer or two.....but I'm far too biased, and upon reflection, believe I'm unable to set them aside, so have a nice day.....:rolleyes:
 

kydsid

Veteran Member
Joined
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Location
Texas
TDI
2012 Passat
I watched someone in a 11' Jetta pull up to the B99 pump the other day, clueless and pretty much told me I am a hater of the world for telling him his DPF couldn't handle it.

There are far too many variables to assume that that B99 would be problematic (though there is a lot of evidence to suggest it is a bad idea at best and that you were right in warning the person if they are truly uniformed). DPF life is concerning in these vehicles since they are not serviceable. But that is just one piece of the puzzle.


The fact is that bio use in a CR goes way beyond a simple idea. For instance bio supporters will point to post injection as the biggest hurdle. They will say manufacturers that use this method (almost all) should be pressured to change to an exhaust stream injection point like on the duramax and some CAT engines. However the duramax engines state only able to burn B20. Same statement Ford, Dodge and most of the rest make with theirs.

Mechanically we should be fine with running it, though with some consequences that increase along with the percentage of bio in the fuel. Unfortunately we are all more or less beta testers these days. Though it's better than the 2007 days when we were alpha testers for Ford, Chevy et al.

Anyone interested in learning some more should check the literature out:

Popular Mechanics Primer on why
Effect of Biodiesel Blends on Diesel Particulate Filter Performance
COMPARISON OF NITRO-POLYCYCLIC AROMATIC HYDROCARBON LEVELS IN CONVENTIONAL DIESEL AND ALTERNATIVE DIESEL FUELS
Effect of Biodiesel Blends on Diesel Particulate Filter Performance
Effects of Biodiesel Operation on Light-Duty Tier 2 Engine and Emission Control Systems
Impact of Biodiesel on Ash Emissions and Lubricant Properties Affecting Fuel Economy and Engine Wear: Comparison with Conventional Diesel Fuel
Clean Diesel and After-Treatment Systems
Chevron Oronite Papers
Biodiesel and Engine Lubrication
 
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oswegoPD

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Only a matter of time for the DPF or HPFP to go out on this one
 

Softrockrenegade

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Howellbama, NJ
TDI
None...2011 Golf DSG (replaced by VW W/) 2013 Passat SE 6M(bought back) Current 2017 sportwagen TSI 4Motion.
I watched someone in a 11' Jetta pull up to the B99 pump the other day, clueless and pretty much told me I am a hater of the world for telling him his DPF couldn't handle it.
And I'm sure the salesman told him not could run bio when he was purchasing the car as well.
 

DmaxSmoke

Active member
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Oct 7, 2013
Location
Whitmore Lake, Michigan
TDI
2014 Passat TDI SE 6MT
According to GM I can only run B5 in my Duramax, but I have run up to B100 throughout the years w/ no problems. Currently at 163k miles. It all boils down to what amount of testing they are willing to pay for. Like any industry, just because a mfg hasn't tested and "Approved" something doesn't mean it isn't safe. That said, I haven't run any Bio diesel in the passat, simply because its not readily available where I fuel most of the time.
 

VeeDubTDI

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Springfield, VA
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The viscosity difference between biodiesel and diesel causes the biodiesel to wash past the oil control ring during post-injection during DPF regeneration. The biodiesel slowly dilutes the engine oil and can cause problems both due to the dilution of the lubricating properties of the oil and excessive oil level. This is why VW is cautious on the DPF-equipped cars and why they recommend checking the oil level more frequently in Illinois where higher percentages of biodiesel are mandated.
 

dzcad90

Rolex & gin
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Mar 15, 1999
Location
Joliet, IL USA
TDI
Jetta - 97 (RIP), '03 (Sold), '09
The viscosity difference between biodiesel and diesel causes the biodiesel to wash past the oil control ring during post-injection during DPF regeneration. The biodiesel slowly dilutes the engine oil and can cause problems both due to the dilution of the lubricating properties of the oil and excessive oil level. This is why VW is cautious on the DPF-equipped cars and why they recommend checking the oil level more frequently in Illinois where higher percentages of biodiesel are mandated.
Know what's crazy.. They don't tell you this when you buy the car. I've had my 2014 for a couple of months now and I haven't gotten a letter about this either. (Maybe it's in the owners manual now.. I haven't had time to spend much quality time with it.)

Seeing as how this is supposedly a large deal, I'd be concerned that it's not made more public when buying the car. That being said, my '09 never ran high on oil. However, I always sought out the places that supposedly sold straight D2. Usually they were 10-30 cents per gallon higher.
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
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This amuses me: I would be highly reluctant to take a dealer salesperson's advice on any aspect of how to operate any automobile I was purchasing. If you see a pump with fuel that appears different from pure diesel, seems a little research is in order before filling your car with it. Relying on advice that you may not get or may be bad seems to be a faulty strategy.
 

dzcad90

Rolex & gin
Joined
Mar 15, 1999
Location
Joliet, IL USA
TDI
Jetta - 97 (RIP), '03 (Sold), '09
This amuses me: I would be highly reluctant to take a dealer salesperson's advice on any aspect of how to operate any automobile I was purchasing. If you see a pump with fuel that appears different from pure diesel, seems a little research is in order before filling your car with it. Relying on advice that you may not get or may be bad seems to be a faulty strategy.
On the flip side of that coin...

Where do you suggest owners get this information, and would you trust that source?
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
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'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
Start with the owners manual. In Illinois VW has also sent letters to owners regarding biodiesel usage above 5%. Maybe they haven't caught up with you yet. And of course you can read here: there's lots of good data.

If I bought an ethanol friendly gasoline powered car I could read up on what percentages to use and their impact on the vehicle performance an longevity. Same with diesel and biodiesel. The difference is that in no place does VW say TDIs are mixed fuel vehicles. Why anyone would think it was OK to run anything but ULSD in their car without doing some research is a mystery to me. Isn't that what it says on the fuel door?
 

FormerOwner

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Alabama
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2013 Passat TDI SE 6spd; Former Owner 02 MkIV wagon
I simply want an explanation from VW... any of you know an employee with possible answers?
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
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South of Boston
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'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
They're not going to give you one, because they don't want the liability. You'll have to draw your own conclusions based on owners' data. But there are variables here, one of which is fuel quality. Here's what you do know: VW allows more than B5 in Illinois, cautioning owners to watch oil level to make sure it doesn't rise. And I've read about folks here running B20 with no issues...so far.

Maybe someone knows a VW employee who'll talk "off the record."
 
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