Why not use even less expensive home heating oil which, from what I understand, is basically diesel without the road tax and red dye added. Cheaper still than road taxed diesel just has red dye to identify it as home heating oil.


Home heating fuel oil is slightly heavier than diesel fuel but shares similar heat-producing properties. A diesel engine produces approximately 139,000 BTUs
(British Thermal Unit) of energy per gallon, the same as heating oil’s 139,000 Btu per gallon. Home heating fuel oil No. 4 and Home Heating Fuel Oil No. 6 offer slightly higher BTU content.


https://sciencing.com/about-6726131-diesel-vs--home-heating-oil.html