I sent an e-mail to them:
Have you done emissions testing on your engines? I'd love to get an emissions profile. In particular, I've heard that combustion of the glycerin in the oil creates carcinogens. Have you tested emissions for this?
Also, coking and polymerization are big concerns when using vegetable oils in combustion. Do you have any experimental data to show expected engine life?
Their response:
within a defined frame of conditions - like suitable engine modification, fuel specifications and operating/servicing conditions - you can run on vegetable oil with no harmful effects on durability and emissions.
About carcinogenity I have no final opinion and experience. I know this matter was brought up and seriously discussed in the late 80ies/early 90ies (acrolein), but seemed to have lacked evidence.
Best regards
Klaus Elsbett
Anyone care to comment?
By the way, some people have pointed out that food-grade vegetable oil is significantly more expensive than gasoline, even now. But apparently, oil processing plants press a number of grades of oil from their presses, only the highest of which ends up on the grocery store shelf. Low grades of vegetable oil are available a much lower prices (or even free). Even low grades of oil from the presses are significantly better than waste vegetable oil, which is full of water, food particulates, and free fatty acids.
Caoimhan