When my wife and I spent our honeymoon in the Sierra Nevada mountains (Spain, not California), we had a multifuel hiking stove, the MSR WhisperLite Int'l, and 1.5 liters of the only fuel we could get (not without difficulty) out in the boonies, gasoline. The stove worked fine, but at the end of the trip we had 750ml of gas left. We couldn't take it on the plane, so we had to get rid of it, but did not want to just pour it down the drain or, even worse, onto the soil. We were able to find someone willing to pour 0.5l into their car, but that still left us with 250ml of gasoline. It finally ended up in the hotel room drain the night before our flight home, but that wasn't an easy decision
Upon returning we decided to try the rapeseed biodiesel they sell at certain gas stations. Not only is it slightly cheaper than regular diesel or gasoline, it's supposed to be biodegradable. So we got some for our new year trip (3 nights in a tent in half a meter of snow @ -20 deg.C) and it turned out that it didn't work
The biodiesel didn't freeze up at -20, but the stove wouldn't catch. Only preheating with lots of soot, but no blue flame. Back home, when it got warmer, I tried again outside (this time the fuel was at room temp.) and still no luck. Twice it did get going, but only for less than a minute.
Today I found info on this subject (
Biodiesel in a camp stove - BioDieselNow - Renewable biodiesel fuel), and now I see that we should have bought the heavier and more expensive MSR Dragonfly. Oh, well. Thankfully Svietlana is a diesel, so she'll get 1.5l of bio when spring gets around.