PawPaw_n_Gram wrote:
Diesel fuel used to be cheaper than gasoline. At that time it was actually possible to make a diesel MH cheaper to run over a five or six year period than a gas MH enough to pay for the price difference between the two units.
Diesel has always gone up in price in the fall and winter because of the increased demand for heating oil in the northern/ northeast US. Heating oil and diesel are very similar so demand exceeds production capacity at times. The colder the winter, the bigger the supply gap.
The introduction of ULSD to combat some of the massive pollution issues with old style diesel fuel has raised the cost. It also raises some of the cost due to changes needed in the infrastructure to store and deliver ULSD. I remember diesel fuel price of 30 cents a gallon when I started driving tractor trailer back in the '70s.
There have also been conversions of some refineries which has resulted in more supply of gasoline and lower supply of diesel.
and there is the right answer. Diesel alway has gone higher during the winter months because the same basic crude stock is used for #2 heating oil. And more heating oil is needed during the winter months there by driving up the ulsd diesel price. Demand is up on the #2 oil which both heating oil and diesel are made from and supply is down and that drives up the price.