Originally Posted by MadScience
I've had friends do both biodiesel and WVO conversions on older diesels, including one 7.3 van to WVO. You need to change out _all_ fuel line. If you miss some, it will eventually break down and clog.
The WVO needs to be filtered, which involves multiple containers and pumps.
The long term report on WVO was that while it worked, having drums of gross stuff sitting around in (a cramped bay area) driveway wasn't wonderful.
I seriously considered this, when I was commuting 150mi/day back in 2008 or so, as gasoline prices near me were moving toward $4/gal. After much research on the topic, I came away with a few major concerns, that had me never pull the trigger on it, and bought a 3cyl Geo Metro instead.
To make it worth while, you have to be consuming a lot of fuel/week. Then it becomes a serious hobby/en-devour
Your garage or side yard becomes a mini-refinery, flammable, stinky
Harvesting waste veggie oil slop from the 'round back' area of a restaurant does not appeal to me in the slightest
It's not 'free' fuel. By the time you convert your vehicle $$, gin up a 'still' $$, harvest waste oil, and include the cost of consumables methanol (to titrate), filters, fuel to heat while refining the stuff, disposing of the byproducts, it really adds up. Some estimate it costs about $2-$3/gallon AFTER you convert and build a still. Not including your time, which has some cost, no matter how you look at it.
For me, after the novelty of the build wore off, the art of refining would be fun one or twice, but would become a chore. YMMV