Flynn wrote:
Fuel duty went up about a month ago that will be the source of the rise in price. I love petrol but I always like to have a diesel car as well as a petrol car because you can make biodiesel and run the diesel off that. Also I am planning to get my car modified to run on vegetable oil. These are both ways of avoiding the government fuel tax. And diesels aren't as slow as you might think either! You can still have high octane (or should that be certane?

) action especially if you fiddle them because diesel lumps are stronger than petty lumps so they have more performance leeway.
Yes, you can make biodiesel.
But not at your home you can't.
For a start your home insurance will not cover you for any significant amount of methanol stored/used in domestic premises.
Depending upon the model, your car will run quite well on a 25% mix of vegetable oil to diesel. Any more and you will need to run it as duel-fuel and start on pump diesel then switch to heated vegetable oil....you will then need to remember to switch it back to pump diesel several miles before you stop the engine (the problem is the viscosity....quite apart from the stress thicker oil puts the engine injection system under you have to remember that if the oil is thicker less gets pumped through the injectors).
Biodiesel made by the transesterification process is not suitable for engines made much before 2000.....some have problems with the seals in the system...and much of the oil so made is insufficiently "washed" to remove the byproducts of the process.
Now we come to straight vegetable oil. You can run your car on it. Yes, you can. But not if you buy it from a shop. Let me run this through with you. Oil bought from a shop is FOOD oil....and carries a zero rate of vat. But ONLY if used as a food. If used as a FUEL it then carries the fuel vat rate. Not paying it is tax evasion and is [obviously] illegal !
So: you can get away with using straight vegetable oil (up to 2500 litres a year is [fuel] tax free under the biodiesel simplification scheme) but you have to pay the vat on its use.
I've been running my van on 33% recovered/filtered vegetable oil for two years now....some 3000 litres @ 65p/litre.
It ISN'T as easy as the internet sites make out....you WILL need to change the fuel filters more often than if running on pump diesel.
And if running on rebated diesel.....there are plans to make the smoke test on the diesel mot also cover as a detector for rebated fuels....you should note that if the revenue stop you and your vehicle is "running on red"....you will wave goodbye to the vehicle AND its load...AND pay a hefty fine AND the costs of transport to the impound.