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Blending Biodisel?

saucer

saucer

Leadfoot
I'll be reading up on this more, but figured we could use a discussion on the pros and cons of running a B5 blend.

I filled up my first tank today with some Shell Ultra Low Sulfur and was hoping to see a label boasting a 3% blend as I've heard is becoming common - but didn't notice anything. There are quite a few biodiesel stations around here, but only 2 offer blends as low as B5 - which is the maximum recommended for the new CR TDI.

Is anyone blending their own from pure ULSD and B100? I would like to make sure I get the ratios right if I attempt this...
 
saucer

saucer

Leadfoot
Found a good formula posted on tdiclub.com (thanks "scurvy")

Vt*0.05 = Vb*Bc

Vt = volume of tank (to 'full' level)
Vb = volume of biodiesel/blend
Bc = Biodiesel concentration percentage (i.e., B99 = 99% = 0.99)

Solve for Vb, add at most that amount to stay at B5 or less.
 
saucer

saucer

Leadfoot
So for a 14.5 gallon Golf TDI (pretty easy if you're using B100):

14.5*0.05 = Vb*1.00
.725 = 1Vb
Vb = .725 gallons or about 92 fl oz (to be safe)
 
P

pvivino

Ready to race!
I used to rum my Mk4 TDI on B20 with no problems. I'm out of the diesel loop now but it seems like VW is being conservative. The biggest fear I always had was the gel point in cold weather. Not a problem in June.
 
saucer

saucer

Leadfoot
yeah the new diesel compresses at something like 29,000 psi, so there's very little tolerance for different fuels now.

some guys on clubtdi have mentioned running B20 with no problems, but with such a sensitive fuels system, there's no way I'm risking anything until there's some hard evidence of reliability.

I shopped around for a MK4 but couldn't find anything with decent mileage :(
I would have LOVED to convert to SVO or WVO!
 
TDI110

TDI110

O_o
I asked around regarding this topic before I made my decision to buy the 2.0 TDI. Needless the common answer was to keep away from bio-diesel with the new CR engines. There is even a sticker on the inside of the gas door that makes that clear.
 
TDI110

TDI110

O_o
Good article saucer. I never really thought about Post-injection fuel, since I am by no means a gear head.

This particular statement got me thinking,
"biodiesel has been heralded as a lubricity additive helping keep fuel system components like the moving parts inside fuel injection systems operating smoothly, the bitter irony here is that, when post-injected, it tends to dilute engine oil and interacts with additives and increases the possibility of engine wear."
Click to expand...
For the time being I will stick to conventional diesel and follow the service intervals that the manufacturer recommends.
 
P

pvivino

Ready to race!
saucer said:
I shopped around for a MK4 but couldn't find anything with decent mileage :(
I would have LOVED to convert to SVO or WVO!
Click to expand...

Sold my 2000 mk4 Jetta TDI with 225k miles. The guy thought bought traded in a 1991 Jetta TDI with only 125k. Both prime candidates for conversion.
 
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