If the "off-road diesel" or heating oil that you are getting is the old Low Sulfur Diesel (500 ppm sulfur) or 500 ppm heating oil, it is good to go in any diesel engine. If, however, your off-highway diesel or heating oil is coming off most any pipeline, it will almost certainly be ULSD (15 ppm sulfur or less). Any ultra low fuel sold as diesel, on-highway or off-highway, will have a lubricity additive injected into it at the fuel terminal rack, as it is being pumped into a fuel transport. Ultra Low Sulfur heating oil, however will NOT have the lubricity additive in it, resulting in heavy wear on fuel-lubricated injector parts.
The lubricity additive is injected at a rate so as to achieve less than a 520-micron scar on the HFRR test (High Frequency Reciprocating Rig) in the US...it is a 460-micron max scar requirement in Europe. ULSD blended with 2% soy-based bio fuel will produce a 320-micron scar on the HFRR (this is great performance)...additional bio will produce no improvement (B30, B40, etc., will still get a 320-micron scar).
As I mentioned on another post, Cat supports up to B30 in their heritage-Cat engines (3208, 3306, 3406, 3508, C-series, etc), but will support no more than B5 in their heritage-Perkins (Perkipillars). Higher than B5 in rotary-type fuel pumps (as used on Perkins, VW, Powerstroke, Duramax, Mitsubishi, etc) produces high wear rates and failed pumps (Humvee fuel pumps all had to be upgraded with hardened components when the military went to jet fuel in all their military vehicles (jet fuel can have no lubricity additives since turbine engines have trouble with it).
Swedgemon
Somewhere in Kentucky
GM-90 6/1