Dont use oil from any big chains unless it is liquid at room temp- otherwise it is a big pain in the neck to work with- besides, McDonalds is one of the worst places to get oil from- all nasty and stuff, same with KFC, BK, etc. Try your smaller places like chinese, or where they migh broast chicken, or a bar and grill place.
My 6.2 does have better power at the higher gear/lower rpm range, but that is only because my IP is damaged slightly from not returning the diesel to the tank and heating up the IP.....but thats another story.
There simply is way too much to doing this than you may think. You have to have a way to collect, either dumping or pumping. Then you have to filter and dewater, for me I use a centrifuge. On the truck you need a seperate tank, fuel lines, filter, etc. The lines need to have coolant lines around them to keep the VO liquid in the cooler times of day. The filter needs to be heated by coolant, you need at least two valves, supply and return, all that wiring involved. If you want to get legal, a road tax is involved, and fee for collecting of raw material(WVO) otherwise you may be caught and fined.
All these things have to be taken into consideration, plus others I haven't mentioned, believe me. I am not trying to convince you not to do this, it just takes more than you know unless you have first hand experience.
Check out my setup here
You cant use copper or steel, you have to have VO up to temp before switching, a seperate pump might be needed or you could ruin the IP, dont use high performance injectors, change your engine oil more often, etc, etc.
Biodiesel can be very dangourous, a few places have blown up from bad reactions, if you want the smell of french fries, you wont very often, becuase you will get used to the smell, and when others say they can smell your exhaust, you wont be able to.
bradnear1987@yahoo.com for direct questions.
I had fun with it at least, so somebody else is sure to as well.....