I was on the empty line in the MX5 when I filled up and I have the receipt here actually:
39.88L @ 138.7p = £55.31
Christ knows what mpg that gets me, I reckon I'm on around 200-250 miles per tank given that a a 50 mile round trip seems to use about a quarter of a tank.
So to visit Alan would be 3/4 tanks I reckon, which looks like around £150-£200 of petrol
I need another veg oil burner!