I have a about 100litres of vegetable oil that I haven't recycled (I actually bought it for fuel when I had a diesel car). I've recently opened it and it has a slightly stale taste. I've used it for frying eggs and other cooking and it's actually more of a stale smell when cooking than when you eat the food.

I've had no noticeable reactions when using it and it hasn't made me ill, but I just wondered if there were any suggestions as to what to do with it. I suppose I could always convert to bio-fuel for step-sons van, but I thought maybe adding herbs or spices might help.

spray weeds with it. It smothers them in a day or so then they go brown. oil breaks down easily in the soil.

Thanks for that, but main weeds we have here are dandelions and nettles and I eat them so don't want to kill them. We do have a problem with some large leylandii which someone told me could be killed by drilling the trunk to the core at ground level then pouring diesel into the drilled holes. If vege oil would do the same, then that would be a good use.

I was really wondering if there was any way of removing the stale smell.

For me rancid oil is just not worth the trouble. I make soap as a hobby and know a little bit about oxidization of oils. It's a continuous process that only gets worse and worse smelling. The oxidization makes the oils unhealthy for human consumption (free radicals) and pretty much ruins it for about anything else. I've tried racking my brain for ways to save soap that had gone rancid and finally came to the conclusion that--sad as it may be--returning it to mother nature was the best thing. I just grated it up and spread it all over the the back. Sounds like bio fuel is the best option.

Dave, by your comments this is SVO? so no need to do anything with it can be used as a biofuel the way it is, i know individuals that run two tanks, one diesel for start up and they then switch over their WVO, ie..... used fryer oil, all they do is run their oil thru a coffee filter to get the trash out of the oil, when they get close to their destination they switch back to diesel for easy start up, the used oil will congeal as temp's cool if it is not processed so they run a copper line around the exhaust to warm up the WVO to help keep it liquid under these circumstances and they have been doing this for several years. no engine issues except for the normal rubber parts issues when using biofuels, i have heard some are mixing their own 80/20 blend, 80% diesel/20% bio during the summer months

you could also use it as a heating oil

regards Stark

Thanks Stark, I used to do that myself and my car ran great off straight filtered Vege Oil, but I did preheat it using radiator water to lower viscosity. Is it OK to just pre-mix with diesel, that would be easiest. No problems with particular engine types or filters?

Using a B20 mix can cause a filter issue (clogging), due to the veggie oil cleaning the fuel system, all depends on how dirty the fuel system is, This is the most common problem when someone starts using large percentages of biodiesel (if you are only using B20 or less then you may never have the problem). how hard is it to change the fuel filter/expense? vs worth using the oil for transportation, remember during winter and you could end up gelling up the tank, lines and filter if not prepared for it, a test could be done making a small amount of B20 in a glass jar and see what happens, any separation or gelling and at what temp.. there has been an issue with the newer engines due to viscosity issues of Veggie oil, recently heard that some are running B70 in summer and B50 in winter using acetone, kerosene or unleaded to thin the VO, but now you start getting into cost issues, time, etc......

To be safe i would wait till summer no reason to have a fuel issue during the winter

regards Stark