Sir,
I purchased a 1982 Mercedes 240D diesel. These old diesels will all run on used cooking oil [also known as waste vegetable (WVO)]. I have run mine for more than a year on 100% used cooking oil with no modification other than a larger fuel filter. You do not have to spend hundreds of dollars for a large capacity diesel filter. I bought a large water filter at the hardware store for around $30. I use the wound rope or string insert that you can buy for less than $20 per pair. It works great for a fraction of what an auto parts store will charge for a diesel fuel filter. If you use new oil from the bottle the larger filter is not necessary. If the temperature drops below freezing you will need to mix [the WVO] with [petroleum-based] diesel to thin it, but otherwise you are good to go. You can also run motor oil in them and I understand they will also run on transmission fluid. I have not tried running 100% motor oil but I have added several gallons at a time to a tank of diesel. There are millions of them still around. Some are still in remarkable shape. The old engines are bullet proof. You can still buy every part new for the cars. I recommend the 1981 to 1985 Mercedes diesel cars. I am not sure about ones older than this. They started changing the engines and injection pumps on the newer ones. Hope this helps, – Ken
JWR Replies: In cold climates, owners may need to add a fuel tank heater. As previously discussed in SurvivalBlog, when burning WVO or WVO blends, it is preferable to have two fuel tanks: A small one containing only standard #2 diesel fuel, and a main tank containing WVO or a WVO blend. The engine is started and warmed up using the small tank, then switched to the main tank. Then, a few minutes before shut-down, the fuel supply is switched back to the small diesel tank. This leaves only “dinodiesel” in the fuel lines and hence eliminates most problems with hard-starting.
Ready Made Resources sells a well-proven WVO to biodiesel processing system. Properly blended B60 biodiesel containing WVO can reportedly be used even in vehicles with more sophisticated fuel-injected engines.
BTW, from a preparedness standpoint, the best diesel passenger cars to look for is a older (pre-turbo) Mercedes built on a W123 chassis, specifically the 240D and 300D models made from 1977 to 1985. I recommend the “T” designated “estate” station wagons, since they a have a lot more cargo room than a typical four door sedan. This configuration also provides room for an auxiliary fuel tank, as described. For a utility-type diesel vehicle, I’d recommend getting a US Army surplus a M1008 CUCV pickup.