Can anyone explain why is diesel more expensive than normal petrol?

Fluffs questioned:

Can anyone clarify why is diesel more pricey than habitual gas?
I also judge it takes less to manufacture or refine but it cost more, why?
Would it not help the farmers, car drivers and the state if Diesel cost or Tax was less.
Diesel cars are also shown to be more fuel efficient, why is it not encouraged by sinking the tax or cost of them.
Import and Regime Taxes, licensing, Stamp duty, conveying fess, tyres, parts and additional cost of a vehicle and running cost must be based on fuel efficiency.
Franc.

Can anyone explain why is diesel more expensive than normal petrol?

Fluffs questioned:

Can anyone clarify why is diesel more pricey than habitual gas?
I also judge it takes less to manufacture or refine but it cost more, why?
Would it not help the farmers, car drivers and the state if Diesel cost or Tax was less.
Diesel cars are also shown to be more fuel efficient, why is it not encouraged by sinking the tax or cost of them.
Import and Regime Taxes, licensing, Stamp duty, conveying fess, tyres, parts and additional cost of a vehicle and running cost must be based on fuel efficiency.