Frequently Asked Questions

Q: Do you really run on waste vegetable oil (WVO)?

A: Yes! In the summer of 2004, about 1/3rd of our 14,000 km (8,700 m) trans-continental journey was on WVO. (The other 2/3rds was on diesel due to expediency and injury.) In winter 2005, we did a 1100 km (700m) trip, using only 50 l (13 g) of petro-diesel, again due to expediency. My goal for summer 2005 is to plan better and be in less of a hurry, and to go 100% biofuel.

Q: How fast will she go?

A: That depends on how big a cliff you push it off of! Seriously, it cruises on flat or gently rolling terrain at 100-110 kph (65-70 mph) pretty well -- as long as there's no wind. A stiff headwind can make it difficult to hold 100 (60). Mountain passes take it down to about 70 kph (45 mph). On one run from Oregon to Michigan, our average GPS-measured rolling speed was 98 kph (61 mph). It's no sports car, but it gets there!

Q: What is her fuel economy?

A: That depends on how big a cliff you push it off of! Seriously, it varies quite a bit, depending on speed, wind, and fuel type. We can depend on a solid 18 l/100km (13 mpg) over long Interstate highways at 100 kph (65 mph). We've calculated as good as 16 l/100km (15 mpg) at highway speeds with a nice tail wind. Biodiesel seems to be slightly less, straight vegetable oil seems to be slightly more. But the biggest factor is speed (or wind): slow down to 90 kph (55 mph), and we get close to 13 l/100km (17 mpg). Slow down to 70 kph (45 mph), and it will get about 12 l/100km (20 mpg)! The Floscan monitor shows instantaneous fuel economy in better than 12 l/100km (20 mpg) for extended periods at lower speeds. Uphill instantaneous fuel economy is as low as 34 l/100km (7 mpg).

Q: Where do you get your waste vegetable oil?

A: We collect it for free from restaurants. Burger joints and bar-n-grills are poor choices -- the high concentration of animal fats makes the oil too thick. Lots of french-frys fills the oil with water-holding starch. Oriental restaurants seem to have the best oil. We prowl back-alleys, looking for oil dumpsters, open the lid to see if it's particularly nasty, dip a stick in and see what the consistency is and where the "crud level" is, then ask for permission, then begin pumping!

Q: How much did your conversion cost?

A: Way too much to justify! Although "free fuel" is enticing, this was not done solely for economic gain. I did a number of expensive things that I would not have done if my primary goal was to travel cheaply. For example, I have over US$1,000 in data gathering equipment installed, and spent US$1,700 on a diesel-fired coolant heater! Other expensive items were the Racor and Vormax filters, about US$500 for the pair, and I used US$250 worth of valves to do fairly complex switching in my three-tank system. All together, I probably have close to US$4,000 into it. But I could have used a Neoteric kit for about US$700.

Q: How long did your conversion take?

A: Too long, yet not long enough! I began gathering data even before I bought the vehicle, a full year before conversion. Some days, I'd spend 12 hours or more, just cruising the Internet, looking for information. A well-informed conversion has a much reduced risk of problems or engine damage. I then began gathering components over a period of several months. The final push took about six weeks of nearly daily work, but this included a lot of extra time to build the tanks from scratch and to install instumentation. Some problems could have been avoided if there hadn't been a final rush to get it ready for deadline-based travel. A commercial kit can easily be installed by an experienced mechanic in a weekend.

Q: If it's so great, how come everyone isn't doing this?

A: Well, it only works with diesel engines, which is currently less than 3% of the US auto market. And it is a bit more trouble than pulling up to the pump and saying, "Fill 'er up!" Energy is not yet so expensive that people do more than bitch as the price of gasoline inches inexorably upward -- they aren't willing to inconvenience themselves, either to save money, or to save the environment. As petroleum reserves continue depletion from present near-peak levels, it may well be that WVO will become a valuable commodity, and big business may discover how to get rich from it. But for now, anyone with a sense of adventure, tolerance for inconvenience, and a greater committment to renewable resources than writing an annual check to the Sierra Club can drive for free while recycling waste!

Q: What about pollution?

A: Unlike biodiesel, which has been extensively studied and found to have vast improvements in emmissions compared to petro-diesel, WVO has not been formally studied at all, as far as I can tell. Part of the problem is that WVO is not a consistent, repeatable fuel, so it's impossible to draw conclusions about what emissions any given restaurant may produce. I've found only one study that concerns SVO, using pure rapeseed oil, which is not what is in your typical dumpster. This study indicates that pure rapeseed oil has emissions characteristics that are similar, but in most cases not quite as good as, biodiesel made from rapeseed oil. In particular, there are a lot of variables, such as engine type and fuel temperature, that have great bearing on the emissions of SVO. But either fuel performs much better that petro-diesel fuel in almost all ways.

Is your question still unanswered? Send it to me and I'll add it to the list!