Unlike the first winter, the car (a beaten up Toyota Hilux Surf) ran really well this winter. The reason: better lagging on the fuel lines under the car so that the oil, when heated by the heat exchanger on it's way to the engine, stayed heated. In the previous winter it was being cooled by the minus wind-chill temperatures under the car and so leaving the car powerless. On these occasions, the only solution was to switch back to diesel - made possible because the WVO system we use is a so called 2-tank system.
So now the car is running pretty much trouble free and my focus is on getting the WVO:diesel ratio as high as possible (or do I mean as low as possible?). Anyway, for the 21 months we've been running the car on WVO, and including all times we needed to nurse the car up steep hills by switching back to diesel, of the total amount of fuel we have used, 76% has been WVO. Given a few long summer holiday trips; to Fuji Rock music festival this July (1,100kms round trip), and Hokkaido in August (2-4,000kms round trip), this percentage should be well up, may be even to the 90% plus area.
Of course the more kms we cover, the more money we are saving, despite the criminally low price that fuel is still at - Oh where are the CARBON TAXES?! Although the goal of driving carbon neutrally, rather than cost saving, was the motivator for this project, costs are always interesting to consider. And here are a few details...
While the cost of the car was only 100,000 Japanese yen (JYN), the total costs of equipment and garage fees connected with the WVO 2-tank conversion came to 270,000JYN. We have now used 2180 litres of WVO which comes to a saving in diesel of about 218,000JYN (using average prices over the last 18 months or so).
And in this top graph is a record of the monthly fuel we used in 2007/08. In the winter, the amount of diesel and even kerosene (to prevent the vegetable oil from freezing) are higher than in the summer when the long trips and minimal use of diesel really starts to show. A similar pattern should appear this summer too after the month of June 2009.
Finally, it's worth noting that I finally got around to changing the extra filter (Delphi HDF296) the other day after 8,000kms, and although very dirty, hadn't been causing any problems despite some blogs mentioning that the filters need changing after every 2,000kms or so. This might be down to diligent filtering of the veggie oil before it gets put into the car.
If anyone would like to know more details on this project or WVO systems in general, contact me or visit my homepage where I have or details and useful links.