BMW certifies: All our engines accept a lil' biofuel
In theory, all engines are capable of admitting a small percentage of biofuel mixed with regular fuel without further changes. Actually, a lot of U.S. states and countries around the world already have a small percentage of ethanol added to gasoline (or biodiesel into diesel).
Nevertheless, a few days ago, BMW published a press release and said that all BMW diesels are capable of being run with blends of up to seven percent of biodiesel (B7) without further changes. Regarding ethanol, BMW said that all BMWs are able to run with up to 10 percent blends, if the engine was built after 1998. For older engines, blends up to 5 percent can be also used.
The announcement was made because German gas stations will have a new type of fuel called "Premium plus" which includes a 5 percent blend of ethanol (E5), as well as B7 pumps available almost at every location around the country.
And what's more interesting, BMW also said that the company is waiting until second-generation biofuels arrive before developing E85 versions of its engines. The Bavarian marque also said that none of its engines are E85 or B100 compatible right now.
[Source: BMW]
Reader Comments (Page 1 of 1)
Hank 5:24PM (1/27/2008)
So...I live in upstate NY where every pump puts out gas with up to 10% ethanol, since it had to replace MTBE. What's BMW's recommendation for older engines in such a case? Drive to another state to fill up, or use at your own risk?
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Wildgoosechase 6:19PM (1/27/2008)
Whoop-dee-freeking-doo! Talk to me when you can run e-85 and b20
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eckre 7:19PM (1/27/2008)
dang... must be real hard to do B100 (if you are in bed with oil companies) my old mercedes diesel has been running on B100 for years and years. but you see it must be been ahead of it's time, being 27 years old and all. B07! great~! idiots.
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rgseidl 8:28AM (1/28/2008)
@ eckre -
your fabled 27-year old merc has an *indirect* injection engine with rather poor specific power. Injection pressures are probably around 1000 bar and the injection hole is humongous by today's standards. That means it is not much affected by the ultrafine PM inevitably present in biodiesel. Modern injectors are much more filigree and therefore sensitive to surface erosion.
To minimize turbo lag, modern turbos are also smaller and rev much higher than those in your car. If you use the wrong fuel, they may overrev and fail prematurely, leading to a large repair bill.
Besides, no IDI engine would meet today's emissions standards anywhere in the OECD. It would also be too anaemic to provide the acceleration performance consumers demand from modern cars in spite of the increased weight, some of which is due to stricter crash safety requirements.
Of course, in addition to the engine, the various seals and filters in the fuel system must be compatible with the fuel. Supporting high biodiesel blends doesn't cost an arm and a leg, but very few customers are willing to shell out for such fuels - at least in the EU, where most governments are forcing refineries to gradually replace pure dinodiesel with low biodiesel blends. From a social point of view, it does make more sense for everyone to drive around on B7 than it does for a very few to fill up on B100. The net environmental benefits depend in large measure on how sustainably the biodiesel feedstock is produced.
By contrast, the US passenger diesel market is still tiny by comparison and, it's devilishly hard to meet T2B5 emissions with regular diesel - never mind a boutique fuel.
Btw, B100 has a couple of distinct disadvantages: certain fungi love it and depending on the exact material your tank was made from, it may cause corrosion. Both issues are solved by using a B98 blend instead.
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Mark Seddon 10:05AM (3/11/2008)
My Audi a4 Avant 2.5tdi quattro sport runs on B100. This is specified in the owners manual. The later models are not specified. The only problem is as I didn't need to make any modifications UK road tax, and more recently congestion charges, are high for me. If only I had to convert it to run on bio!
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