I know several people who are living on the poverty line - they simply can't afford to buy a diesel car - petrol ones are so much cheaperto buy. Many older cars struggle to get 28mpg - it doesn't mean the poeple can also afford another £200 tax!!!
As to cooking oil you would be suprised - around here it's very common. At one time ASDA in Llanelli was selling more cooking oil than any other store!!!
Don't you remember the Frying Squad - police cracking down on people using cooking oil whislt it was still illegal.
Look at the prices in the article - cooking oil at 32p and diesel at 72p - now it's 97p and £1.20!!!