veg powered Volvo

You need to get anything checked and approved (and taxed). It is quite possible to run a car diesel engine on cheap "agricultural diesel" without modification, but it is illegal.

The cheapest fuel is used oil from your local chippy as they will let you have it for nothing. You will spend a lot on filters though.

Some info is here

I already have the cold pressed oils and think it would be cool to run my car on the oils I sell. But I don't know about gumming up the injectors. Can I run cold pressed oils and occassionally clean the injectors or do I have to degum the oil 100% of the time? Or is my best move to esterify? We plan to build a food manufacturing facility with a cold press to diesel generator off grid loop. Any opinions on my best combination?

It was somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "voder" saying something like:

Bear in mind I use biodiesel and not veg oil as a fuel and this advice is worth what you pay for it...

If you're using your own clean oil as a fuel and using a two-tank heated fuel system, it's best to start up and shut down on ordinary petrodiesel. This keeps the injectors fairly clean. Some users of vegoil start up / shut down on biodiesel and have reported the injectors are clean as a whistle on inspection.

Whatever you do, always make sure the vegoil system is well up to temp before changing over and never shut down on vegoil if you plan to cold start.