On two cycle diesels, Detroit Diesels are what I am familiar with,
number 1 fuel is not recommended because of its poor lubricating
quality. Diesel fuel must cool and lubricate the mechanical injectors.
To prevent the wax in #2 from falling out of suspension in cold weather
it can be mixed with #1 to lower the pour point.
It's usually better to lower the pour point on on road applications
chemically but you do what you have to do to keep them running.
Ron