Tuesday 8 September 2009

Winter running

I was recently asked about the obstacles to running on vegetable oil in winter, so even though it is still nice an warm (here in the U.K.), I though I'd post an explanation.

All fuels suffer problems at extremely low temperatures, including Petrol,
Diesel and Vegetable Oil. Petrol works to lower temperatures than Diesel
and Diesel works to lower temperatures than vegetable oil. Different
types of vegetable oils work to different temperatures. I have found it
difficult to use neat Soyabean oil below about 0 celcius. Rapeseed oil
seems to work a few degrees colder. The problem with all fuels is that
they first go cloudy, which clogs the fuel filters, and then at lower
temperatures, they go completely solid.

There are a number of ways to work around the cold problem. The easiest
way is to mix in a small amount of Diesel with the fuel. Other things we
have done include putting electrical heating tape on the fuel injection
lines and a heated wrap around the fuel filter. You can read about both
of these elsewhere on this website. Another solution which we haven't
tried personally is to get a twin tank conversion, where the car runs on
diesel until it is warmed up, and then it runs on vegetable oil that has been
passed through a heat exchanger.