1) Vegetable oil must be hot to burn in your Diesel engine. Most SVO burners use engine coolant to heat their SVO. The SVO of course is not hot when your car is cold. You need to run it on diesel fuel to heat up the engine and SVO. When you get to your destination, you need to shut down on diesel fuel as well.
2) If your engine is direct-inject (most newer Diesels) it may not be suited for SVO. See the TDI/SVO Controversy link at right.
3) It will take time to collect, settle, and filter SVO for use.
4) In very warm climates (S Florida, Arizona, etc.) some people burn unheated SVO in their pre-'85 Mercedes Diesels. For most Americans, however, a 2-tank setup is necessary to assure hot SVO.
6) Securing a source of free used vegetable oil can be tricky. It is best to establish a relationship with the owner or manager of the restaurant. Ask them to put the oil into the cubes in which it comes. Ask them if they rinse out their fryers into the oil. Ask them what kind of oil they use. Ask them how often they change the oil in the fryers. Ask them if they salt items before frying them.
7) Stay away from restaurants with nasty grease bins. If it smells revolting, pass it up. If the top is left open, exposing the SVO to sunlight and water, you can bet the SVO will have algae and bacteria in it.
8) Whatever your Diesel car or truck is, you should do specific research on your vehicle. You may need to install an auxillary pump to help with the thicker SVO. You may need to beef up your alternator to use an electric heater. See links above for places to visit to research.
9) Usually, the stock tank is mounted in the truck or hatch, and plumbing to and from the tank is run underneath the vehicle.
10) You will be installing components, wiring, and plumbing. You may need to fabricate or have metal welded. If you aren't familiar with changing your own oil, I recommend hiring someone to convert or studying up before taking the plunge.
Listed here are some features you may or may not want for your conversion:
a) Electric heater. Pictured above, this simple heater costs about $35 to make. I consider it a must for my TDI. It adds about 20 degrees to the SVO temp.
b) Heat exchanger for SVO tank. This can be a copper coil, or a tranny cooler inside the SVO tank. I use a tranny cooler.
c) HIH (Hose-inside-hose) or HOH (Hose-on-hose) plumbing from tank to engine. HIH is better thermally, but quite honestly scares me. If coolant leaked into SVO or SVO leaked into coolant, it's a recipe for disaster! HOH may not heat the SVO as well, but at least I don't worry about leaks, and its job is just to keep the SVO warm.
d) Fuel temp gauge and sending unit. Also easy and cheap to make, you know how hot your SVO is as it enters the injection pump.
e) Backflush. This is a feature that should extend the life of your SVO filter. When you shut down on diesel, you send diesel fuel back thru the SVO filter, plumbing, and finally to the SVO tank.
f) Coolant-heated SVO filter. I use a copper coil wrapped around my SVO filter. The hot coolant flows first through this coil, heating up the filter, before going back to the SVO tank.
g) Looped return or separate return. Most companies which offer SVO kits use a looped return. That is, the Injection pump always pumps more fuel than is needed. The unused fuel gets returned to the diesel tank, usually. On an SVO conversion, often it is looped back into the supply. There are critics of this. Their argument is if air bubbles get sucked into the loop, they can't be purged. With the backflush, air bubbles can be purged. If backflush is not important to you, you can save money by returning SVO to the SVO tank and diesel to the diesel tank.