Go for it. I try to fill up exclusively with B20. Probably best if you're spending a lot of time on the interstate instead of puttering around town, but thats always true with these cars. Don't tell your dealer.

 

From the '15 Manual:

Using diesel fuel with concentrations of methyl ester biodiesel higher than 5% (B5), such as B11, B20,
or B100 when B5 biodiesel is available, is contrary to the terms of your New Vehicle Limited Warranty
and is strictly prohibited.

 

.

 

Thanks everyone for your responses! It some cases it appears to be the only option in my area. I will keep a closer watch on what is being offered. The price was certainly attractive

 

Agreed with staying away from it

 

Save now, regret it later.....

􀁸 The vehicle is warranted to run on diesel fuel containing methyl ester biodiesel in
concentrations of 5 % or less. Never use methyl ester biodiesel in blend levels higher than 5 %
(5 % methyl ester blends are sometimes designated or labeled as B5). The properties of methyl ester biodiesel blends in levels greater than 5%
will void coverage for related engine damage under the Emission warranties or any other
Volkswagen Limited Warranty, unless your vehicle is registered in Illinois.
􀁸 Biodiesel especially in concentrations higher than B5, can attract water and also deteriorate
with age. Small amounts of biodiesel can get into the engine oil, but unlike petroleum diesel, it
does not evaporate over time. This can cause the oil level in the engine to rise and can affect
the quality of the oil and if not detected and remedied promptly, will ultimately result in engine
damage.

 

B7 bio-diesel (up to 7% bio) has been widely used throughout Europe for about 10 years so I'd expect Touareg TDis to cope with that on a global basis - France has introduced B10 (10% bio) but NO VW Group diesel is approved to use it.

 

The engine likes it fine. The super-expensive US-spec emissions system- not so much. The European manual also has a different spec for fuel.

 

As far as I understand, there are two main issues regarding the use of biodiesel in our Tdi Touaregs (7P series, specifically).
The first is that there can be residual free ethanol (of varying quantity, depending on the manufacturing process efficiency) present, which is hydrophilic, and will absorb atmosperic moisture into the fuel, only to release it as water in the fuel at a later date when the ethanol evaporates. Water, and the prefect sliding fit piston/cylinder of the fitted HPFP do NOT mix!
The second is that the DPF is far more easily “permanently“ fouled with biodiesel combustion products, as opposed to conventional diesel fuel combustion products, which can be removed by the self cleaning process provided by the vehicles fuel/exhaust system.

 

The fuel filter traps any moisture in the fuel and the Inspection Service requires the water to be drained at 20,000 miles (30,000 km) or 2 years, whichever comes first.

 

Yes, BlackGrouse, that is what it is there for, and if all goes well, it does it’s job...

 

are there any national brand gas stations that offer non-biodiesel at the car pumps?

 

Minnesota has mandated that all summer fuel sold is 20% biodiesel and winter fuel 5% biodiesel.

Source

 

thanks mpls. Have you seen any negatives with your Treg based on these %s?

 

I have never had an issue with fuel purchased in MN. I've been driving an oil burner since long before the mandate.

I do use power service white bottle but not religiously.

I did get a tank of crap in Mitchell SD at the holiday truck stop.
It pretty much made my ALH Golf a piece of trash.

So there goes the high turnover diesel pumps are going to have good fuel thing.

 

If it's cold out you need to run power service white, period. Diesel turns to wax when it's cold out.

 

I guess I can't agree with you there.
If you buy properly winterized diesel fuel you don't need to add anything. Most stations have gel temperature posted in the winter season.

I've been driving diesels in Minnesota for 20 years and I can tell you I do not add an additive to every single tank through the winter. I do usually add some when we are heading into a long stretch of negative °F temperature ranges, but for the most part I find the fuel to be well treated

The key is to make sure you're buying fuel at a high turnover station
If you're not sure about fuel purchased the fall is the time to use an additive for sure as stations are going through their summer fuel.

Newbies and the unaware could be stranded tho as some stations sell untreated #2 year round (generally these are truck stops but I see it at mid sized Kwik Trips & Holiday stations as well)
The pumps are marked, and there are always treated pumps right next to them, but you do need to pay attention.

 

Well, it's a biological fact that diesel turns to wax if it's not been properly treated, so that point cannot be argued. And I've personally had diesel gel up on me in NY using good fuel but no additive.

 

That's why many countries legislate for winter diesel specifications and changeover dates - lack of that legislation is a downside for motorists.

 

Yep, we have those. The temps were around -20f when the diesel gelled but technically it can happen any temp below freezing so I don't mess around anymore. Took me a full day each time to purge the system with diesel 911 and a damn hair dryer

 

Well, perhaps old marine engineer can add a few observations here. Diesel fuel itself does not actually “gel” or turn to wax at cold temperatures, it is the paraffin (the american version of the word which describes a type of wax, not the European word which describes a kerosene type of fuel) content of the diesel fuel (variable percentages, depending of source) which starts to precipitate out of solution into long chains. Simple physical chemical behaviour. These chains grow and cluster to such a size that they become visible as a haze and depending on concentration, will tend to thicken the fuel. The main issue is that these waxy paraffin chains will grow to the extent that they will entirely block the fuel filter and prevent the engine from running. Some additives will inhibit this chain growth, and some techniques (such as adding kerosene) will dilute the fuel to an extent that the chains will not coat the filter element to the degree that prevents operation. Providing heat to the system (ie. a fuel filter heater, recirculating warmed fuel, etc) will always reduce and reverse this issue, driving the paraffin back into solution and preventing it from forming and causing an issue in the first place.
Refining out the paraffin is expensive, which is why it is only reduced to various levels for various reduced temperature markets. You wouldn't actually want the oil companies to reduce their profits, just for our benefit, would you??

 

Well said, thank you for your knowledge