“You could run a car on that.”
“On what?”
“On the oil in that heating tank. It’s 35-second oil. It’s the same as red diesel. There would be a few people around here who do that.”
In Northern Ireland of 1989, the chance of being caught for using red diesel in a road vehicle was much slimmer than it is now. When I did buy a diesel car, I was never tempted to try running it on heating oil. A neighbour insisted that the heating oil was less refined and would clog up the injectors of the car (whatever the injectors were).
Red diesel in Northern Ireland was agricultural fuel. Taxes imposed on it were a fraction of those paid on road diesel. The red colour came from dye that was added, dye that some people tried to wash out in order to present it as legitimate road fuel (the neighbour said that the dye could damage the engine).
In the Republic, the farm diesel was dyed green, and, judging by the number of checkpoints where Garda and customs officers dipped vehicle tanks for signs of the green diesel, the use of 35-second agricultural oil to run cars must have been a common occurrence.
Given the suitability of farm fuels for running cars, my grandfather’s farm at Huish Episcopi must have provided much temptation in those moments when road fuel was scarce, or was hugely more expensive. Beside a corrugated iron shed in the farmyard, two large tanks stood on brick supports: one contained diesel and the other a fuel called TVO. The more modern Nuffield tractor ran on diesel and the older Fordson and Ferguson ran on TVO.
The operation of the TVO tractor seemed complicated. It had two fuel tanks. There was a smaller tank that contained petrol; it was used to start the tractor. Once the engine was running well, the driver would switch to the larger tank containing the TVO, which was apparently like paraffin. The worst mistake a driver could make was to forget to switch from the petrol to the TVO. Petrol was expensive and there was never more than a jerry can of it kept on the farm.
Both diesel and TVO tanks had hoses fitted to allow the filling of the tractors. To have used the red diesel for a car would have been a simple matter of pulling up beside the tank and putting in the fuel (unlike trying to extract it from a central heating tank). Perhaps the excise men kept an eye on such temptations.