Originally Posted by LubricatusObsess
It is the exact same fuel except the red dye added to the off-road fuel. Why? You pay less taxes for the off-road fuel because you aren't using a vehicle on the road, therefore aren't subject to fuel tax to pay to fix the road.
A decade earlier, they were different fuels. The off-road had higher sulfur content and by default, higher energy content (less heavy ends stripped out), and was cheaper to make as well. EPA mandated identical low sulfur limits by 2010.
If you don't fill up often, you don't save much. Guys running bulldozers do.
There's nothing preventing the use of taxed diesel for off-highway use. I say off-highway because it would be perfectly legal to use untaxed diesel on construction equipment or other off-highway uses. I believe it's even used in diesel generators.
I know of one application where taxed diesel is used for an off-highway use. The Disneyland Railroad reportedly uses B98 biodiesel, with most of the base oils coming from used cooking oils from their restaurants. They've opted to use taxed diesel for the remaining 2%.