Reply #39: Most biodiesel is used as blend stock

[jmowreader]

There appear to be three "blends" of biodiesel.

B5 biodiesel is 95 percent petroleum diesel, 5 percent biodiesel. You can run this in any diesel engine without changing all the fuel lines.

B20 biodiesel is 80 percent petroleum diesel, 20 percent biodiesel. You can run this in most diesels--older Japanese diesels appear to be the exception.

B100 biodiesel is pure biodiesel. Your engine needs biodiesel-proof lines on it to use this fuel.

Next problem with homemade fuel: road use tax. If you go to the local DMV and tell them what you're doing, they will set you up with the same forms truckers use. You report and pay fuel tax on a large truck based on mileage, not on gallonage, which saves them big bucks--especially operators that run refrigerated trailers and ones who do a lot of off-road service, like loggers and dump truck operators. But if you don't do it, and someone wearing a badge happens to take a whiff of your exhaust, you are severely screwed.

I love the calculation: 500 gallons of fuel burned means 500 gallons of waste vegetable oil required. Not true--the saponification process used to make biodiesel means a lot of your waste oil winds up as soap. I've heard wildly varying numbers, but 2 gallons of oil for each gallon of fuel looks like a good one.