Can you MIX waste motor oil and vegetable oil? Will they work in diesel engines if mixed together?

Question

We do not have access to enough vegetable oil to provide all the fuel that we need. We can get waste motor oil. Can you mix the two oils and have them work in diesel engines? We will also thin with biodiesel. Will the resultant mixture gum up?

Answer 1

Waste mineral oil is actually lube oil and as such is used for protecting the engines rather than burning in them to produce energy.  So you will be best advised not to use these oils to run your trucks.

Even the raw vegetable oils are not good replacement for diesel.  Their molecular weight is too high and there will be  heavy carbon  deposition in the engines if they are used.  So you will need to transesterify them with methanol in presence of a little sodium hydroxide to convert the veg oils to the corresponding fatty esters whose molecular weights are of the same order as those of commercial High speed diesel manufactured from petroleum.  If you are interested it is not difficult to do it in any farm and they have been doing it since more than 60-70 years in US and I can also give the necesssary procedure and refernces.

So please dont use the raw vegetable oils and mineral oils in your trucks and disel generator sets.  If you want you can use them to generate steam or as a source of heating only.

Answer 2

If you want to use waste motor oil the truck is not the best place. Get a waste oil furnace to heat your house and/or place of business. Use the money you save in heating expenses to buy fuel for your truck.

Answer 3

Need a good filter to remove everything that might plug your injectors .

Answer 4

you have to be really careful doing this and change your filters constantly.  Honestly it will work but you'll use a ton more filters.  Also remember any impurities could be bad things to burn in your engine.

Answer 5

No. I stopped it as it caused wax like clumps to form in the wvo.I make my black diesel separate.I use motor oil with NO CHANCE OF ANTIFREEZE IN IT,and used ATF,both mixed with 3 parts diesel.Filter 10 times with blue jean legs.Final filter double blue jean legs.The fuel you can now see thru it.No more than 10% to diesel or if heating 100%.Burns real clean more power.You must get that diesel soot out of that oil,or it will grind your injectors.