Burning unheated WVO is a bad thing for your fuel system and your motor. In my picture album, I posted a chart with a viscosity table comparing diesel and veg oil - it doesn't come close until oil is at 160*F. This means it won't combust completely and will gum up your injectors, rings, etc. Also, with normal fuel blow-by on a cold start, you'll get veg oil mixed into your crank case - it forms a mayonaise-like substance inside; not good.
If you're looking for lubricity only, run a B5 blend, don't blend in WVO. In cold weather, it will drop out of the fuel and cause you the problems above. Bio is a lot more work and it costs more over the long run with the variable cost of methanol and the chemicals you need on an ongoing basis. But, bio shines if you do a lot of short trips or have multiple rigs to feed. Plus, you can run a B20 blend in your home heating oil if that's how you heat your home.
If you go the WVO route, convert your rig to a good heated 2-tank system like the Vegistroke. I'm not an expert, but I've been burning WVO in my '02 Ex with a modified V3 system for 2 years without major incident.
Either way (bio or WVO) if you have a good oil source, I don't think you can go wrong.