Lets Talk Biodiesel

I thought I’d do a thumbnail sketch on Biodiesel, so that diesel engine owners are made aware of the potential problems that can arise from its use.  This won’t be a scientific, in depth study, but just a simple look in layman’s terms that I hope you can understand.

Thanks to our national policy of trying to reduce the importation of foreign sources of oil, movements to increase the use of renewable fuels, such as ethanol and biodiesel mixtures added to gasoline and diesel fuel, respectively, has taken place all across the country.

Biodiesel is most often made from soybean oil and/or rapeseed oil and mixed in with the refined diesel made from crude oil.  It can be made from animal fat based oil (like used french fry oil) but that is very rarely sold commercially.

Biodiesel, when compared to straight diesel fuel can reduce energy efficiency from 5 to 7 percent, causing fuel mileage to drop and may cause a noticeable reduction in engine power.  Plus it can attract moisture in greater volume, doing two things, contaminating the diesel fuel and creating a more favorable environment for the growth of bacteria (or more commonly called algae) in the fuel tank.

Serious fuel contamination can lead to plugged fuel filters causing engine power loss, or missing.  It also can lead to damage to very (very) expensive fuel pumps and injectors.  This kind of damage is often not warrantied by engine manufacturers or extended warranty policies.

I’ve noticed more and more diesel fuel pumps are now sporting stickers saying that the fuel contains biodiesel in percentages from 5 to 20 percent.  You don’t know how much biodiesel is actually in the fuel you are putting in your tank.

Biodiesel, with its propensity to draw in water moisture can cause problems for motorhomes in storage, especially in warmer temperatures.  That again can cause an environment for bacterial growth.

What can an owner of a diesel engined motorhome (or truck) do to mitigate the potential problems caused by biodiesel?  Several steps can be taken.

First, consult your engine owners manual to see what percentage of biodiesel is acceptable.  For my CAT C-7 diesel engine, I’m not to use biodiesel in amounts greater than 5 percent.  I no longer will fill my tank at any pump that has that sticker on it saying “Contains Biodiesel in amounts between 5 and 20 percent”.  I’ll move on to another fuel station.

I also try to fuel up when I’m at one half of a tank.  That way if I’m caught in a situation where I’m forced to use diesel fuel with a higher percentage of biodiesel, it will be diluted by the fuel already in the tank.

I recommend the use of a diesel fuel additive (there are many out there for you to choose from) to offset the biodiesel.  The additives can help to emulsify the biodiesel so it is spread more evenly into the diesel fuel. In some cases, the biodiesel does not mix evenly in the diesel fuel and can “clump” together.  The additives can also keep the fuel pump and injectors clean as well as inhibit bacterial growth.

Keep an eye on your fuel filter/water separator and drain off any water that may be found in the drain bowl. 

I recommend if you need to store your motorhome for an extended period of time, fill the tank as full as you can get it and add a fuel additive.  Marine stores usually have a good selection of additives because boats often spend a lot of time in storage.

Lastly, carry at least one set of fuel filters (I carry two).  That way, if your filters get plugged, you can change them (or have them changed) and be on your way.  Make sure to have your fuel filter(s) changed according to the manufacture’s recommended intervals.

Biodiesel (and ethanol) is here to stay, we have no choice and will have to learn to live with it.  These few simple steps hopefully will keep you rolling down the road and continue to enjoy your travels.

Thanks for visiting and feel free to leave a comment.