When I came to Canada diesel was only 60% the price of petrol. There were few diesel cars in the 60's & 70's. However as soon as diesel cars started to become popular ,the price of diesel started to climb & has not stopped since, now surpassing petrol in cost. We pay the same road tax for both petrol & diesel vehicles. In 1968 I paid 16.7 cents a gallon for petrol, by 1975 it was 35.9 cents a gallon & pay was $3.75 per hour. today petrol is $5.08 dollars a gallon & pay is $ 25.00 to $30.00 dollars an hour. Wages have increased approximately 700%, Petrol has increased by approximately 1,400.00%, so much for disposable income. It is simple, they have calculated how much they can charge & get away with & they are very good @ it. Every long weekend (bank holiday ) the price goes up about 10% & comes down again on the day after the weekend holiday, it's called price fixing in my book, the oil companies call it market forces.. Mick B.