Twitter headlines« Study: Global Biofuel Use Could Emit 9x More CO2 than Conventional Gasoline and Diesel | Main | EuropaBio Recommends Initiatives to Boost Biofuel Use and Move to Second-Generation Biofuels »
Volkswagen To Stick With B5 Maximum For Now
17 August 2007
VW will support only a 5% biodiesel blend (B5) in its vehicles for now, according to Klaus-Peter Schindler of Volkswagen AG at DEER 2007.
We are now restricting the use of biodiesel to 5%. Earlier, [we allowed engines] to be operated with 100% biodiesel, but we are now stepping back to maximum of 5%. The reason for this is that we see oil dilution due to late injection.
—Klaus-Peter Schindler
At the 2006 National Biodiesel Conference and Expo, Schindler said that VW was studying the use of B20, and that the earlier tests of B100 were halted by Volkswagen because of problems with oil dilution and difficulties igniting particulate matter (PM) in exhaust particulate traps. (Earlier post.)
According to guidance released by the National Biodiesel Board (NBB) in November 2005, blends higher than B20 may cause oil dilution—the contamination of engine oil with unburned fuel that makes its way past the piston rings and into the oil pan. This dilution is due to the slightly higher viscosity and the slightly higher density of biodiesel vs. petrodiesel.
High levels of biodiesel present in the engine oil may polymerize over time and cause serious engine oil sludge problems, causing a need for more frequent oil changes. According to the NBB, because the viscosity and density of B20 and lower blends are very similar to that of the pure petrodiesel, “this phenomenon has not been problematic with blends of B20 or lower.”
VW’s experience seems to indicate that on-going changes in injection strategies to minimize engine-out emissions and maximize engine efficiency may have an impact on the dilution issue.
Resources:
August 17, 2007 in Brief | Permalink | Comments (3) | TrackBack (0)
Comments
Posted by: Karkus | August 17, 2007 at 01:01 PM
Biodiesel bubbles burst the world over.
Posted by: jack | August 18, 2007 at 12:29 PM
- I wonder if anyone is redesigning piston rings to prevent fuel dilution of lube oil.
Mr./Ms. Karkus - Can you provide a reference to the data on which your statement that the emissions reduction benefits of biodiesel are big with B2 or B5 and not much greater at higher blend levels?
Thanks,
Mike
Posted by: Mike Haas | August 27, 2007 at 06:34 AM
TrackBack
TrackBack URL for this entry:
http://www.typepad.com/services/trackback/6a00d8341c4fbe53ef00e54ecc713f8833
Listed below are links to weblogs that reference Volkswagen To Stick With B5 Maximum For Now:
It's unfortunate that B5 is all they'll support (instead of say, B20) but you've got to expect car companies to be conservative on these things, since they're the one who suffer in their reputation and warranty dept. if things go wrong.
But let's look at some reasons why B5 really isn't so bad.
1) studies have shown that B5 is realistic for what can easily be produced to supply the entire country's diesel fuel needs. B20 or more would consume unrealistic amounts of farmland and/or displace too much food production.
2) it's better from an emissions standpoint for the everyone to be using B5, than for a quarter of diesel to be B20 and the rest B0. Studies have shown a big improvement for just B2 or B5, but going to higher % doesn't improve emissions that much more.
3) B5 isn't going to have cold weather issues.
4) it's easier on the fuel distribution system and on gas stations if everyone uses B5, instead of some B0,B2,B5,B20,B100 etc.
So from those standpoints, B5 is really just fine for now. Maybe in a decade, when they figure out how to make biodiesel more efficiently, then they'll also have figured out how to make cars run better on B20 or even B100.