80/20 or pure bio? which one?

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Read all the threads - still a little confused on whether to run either a 80/20 blend of bio-diesel or pure bio in my 02 beetle TDI.

There is a local refinery that I can "pull up to the pump" and buy bio-diesel from in my area, so I'm not making it myself and I'd imagine the quality would be better.

Any thoughts? Suggestions?
 
Why not buy which is cheaper? If both the same, go with B100. Even though I live is "Biodiesel Central" (Iowa), the B100 is harder to come by and costs more. So I usually use a blend. Different areas of the country will have better B100 availability. I use it when it is available, but only if the cost is same or less. Cost is more of an issue since I go thru just under 26,000 gallons of fuel a year.
 
Even B2 will clean out your fuel system. So, if you've never run biodiesel, replace your fuel filter now and carry a spare with some tools.

Use B100 and paint peace symbols on your car and get those fueled by biodiesel bumper stickers everywhere....

Shop on price.
 
Originally Posted By: Jim 5
Are there any issues with Biodiesel and DPFs?


None. Thousands of semi's with DPF's and SCR are using bio blends daily with no issues. Bio has no negative effect on DPF. I would step out here a little with no real evidence, and say that bio blends would actually have a net positive on DPF. Reason is that bio actually has a slightly hotter burn. This would, in theory, reduce the amount of soot downstream to the DPF. Because of the hotter burn, bio will kick out more NOx in combustion, but by not being a petroleum product, it actually results in a lower CO level. I came across these findings several years ago when bio was the new kid on the block. Things may have changed.
 
The only issue I have had with Biodiesel (Maximum of B20 per engine manufacturer) is I get higher fuel dilution numbers with it. Im not sure if it simply shows a higher number on the test, boils off less easily or actually manages to get by the rings more. As I understand it thats the reason the engine manufacturer limits it to B20. Higher levels would require a reduced OCI.

PS It also seems to raise the nitration results.
 
Originally Posted By: TiredTrucker
Originally Posted By: Jim 5
Are there any issues with Biodiesel and DPFs?


None. Thousands of semi's with DPF's and SCR are using bio blends daily with no issues. Bio has no negative effect on DPF. I would step out here a little with no real evidence, and say that bio blends would actually have a net positive on DPF. Reason is that bio actually has a slightly hotter burn. This would, in theory, reduce the amount of soot downstream to the DPF. Because of the hotter burn, bio will kick out more NOx in combustion, but by not being a petroleum product, it actually results in a lower CO level. I came across these findings several years ago when bio was the new kid on the block. Things may have changed.


There is little evidence today that would indicate a "hotter burn" in fact, bio diesel generally produces lower BTU's than ULSD. Biodiesel does produce less ash and CO2 in theory during combustion. However the thermal instability of biodiesel vs ULSD can stress injectors, and filters and cause combustion issues that will actually decrease combustion efficiency and as a result potentially cause DPF related issues. Trucks with DPF's aren't exclusive to injector choking; so biodiesel doesn't cause issues with DPF's per say, but I wouldn't go so far as to say it will help them.

The biggest enemy to a DPF is heavy idling and failure to maintain them by having them cleaned at a regular interval.
 
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