Bio-Fuel in diesel

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Mon 22 Sep 2008 11:04
Bio-Fuel in diesel - prm72
Does anyone know if the 2 1/2 % of bio-fuel thats now in all fuels acts as a lubricant in diesel?

Edited by Dynamic Dave on 22/09/2008 at 11:17

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Mon 22 Sep 2008 11:47
Bio-Fuel in diesel - jc2
No lubricant-it's basically alcohol.
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Mon 22 Sep 2008 12:39
Bio-Fuel in diesel - Armitage Shanks {p}
I thought it was up to 5% but I could well be wrong!
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Mon 22 Sep 2008 13:58
Bio-Fuel in diesel - Group B
I think its generally accepted that "biofuel" is a catch all term for all fuels derived from biomass.
Bioethanol is an alcohol for use in petrol engines, biodiesel is a methyl ester for use in diesel engines. ;o)


Nearly every website I have seen stating the benefits of biodiesel claims that it has higher lubricity than normal petroleum diesel, and when added to normal diesel it will improve the lubricity. Its rare that they give any evidence to back this up, but I found this report: snipurl.com/3snf3 .

If you look at Tables 2 and 7 it shows reduced wear on a test component when using a blend of 1 or 2% biodiesel mixed with ULSD, compared with ULSD on its own. It suggests that ULSD with as little as 1% biodiesel can give better lubricity than ULSD with standard additives.

Edited by Rich 9-3 on 22/09/2008 at 14:02

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Mon 22 Sep 2008 16:48
Bio-Fuel in diesel - Sofa Spud
Our local garage sold 5% biofuel for over a year but recently they stopped doing so.
I enquired why and was told it was because 1) ordinary diesel now contains 3% biofuel and 2) it's cheaper.

Edited by Sofa Spud on 22/09/2008 at 16:49

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Mon 22 Sep 2008 20:43
Bio-Fuel in diesel - cheddar
I have done some research into this, it seems that biodiesel in general has better lubricity though the situation is not clear regarding high pressure pumps due to less resistance to shear. Hence the possibility of an increased prevelance of costly CR pump failure is a resistance to its ratification and adoption amongst car manufacturers. As it is some manufacturers authourise fuels with 5% bio only and others up to 20% though it seems that any warranties would be invalidated by the use of B100 (100% bio).

That being said the CR Cummins marine engines used by www.earthrace.net completed 6000 hours on 100% bio diesel with no problems.

A key issue is the lack industry QC and standards for bio-diesel so there is good stuff and there is carp. If standards were introduced then maybe the motor manufacturers would be less reticent. I am wondering if perhaps 95% bio with any necessary additives to protect CR pumps and perhaps boost cetane so performance is comparable, IIRC an engine will typically be 9% down on power using B100 rather than conventional diesel.



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Wed 24 Sep 2008 12:38
Bio-Fuel in diesel - prm72
Thanks all, probably no need to use the Millers additive for lubricating the pump anymore then?
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Wed 24 Sep 2008 12:41
Bio-Fuel in diesel - cheddar
What fuel are you using?

Also in environmental terms there is no benefit in using diesel that is 2.5% bio and then adding Millers, better to use normal diesel, Shell etc.
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Wed 24 Sep 2008 14:35
Bio-Fuel in diesel - prm72
Ceddar, just using normal Shell derv, i did try the V- Power but my mpg dropped by 5mpg.
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Wed 24 Sep 2008 15:55
Bio-Fuel in diesel - cheddar
using normal Shell derv i did try the V- Power but my mpg
dropped by 5mpg.


Strange, I reckon mine is slightly more economical on V-Power, it costs about 7% more which equates to about a 3 mpg benefit to pay for itself and I dont think it quite achives that though I also think it runs a little more crisply and V-Power should lube the pump etc better.

Unlike my V6 Vectra than was more economical on the old Optimax to the extent that it made it cheaper to run.
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