"The Daring Dufas" wrote in message

When heating oil is cheaper than diesel, sneaky
truck driver will run their trucks on it. That's
the reason for the red dye in the diesel fuel.
When The DOT inspects a truck, the inspector may
look at the color of the fuel to determine if the
trucker is trying to avoid the over the road fuel
taxes.

TDD

Opposite. The heating oil is dyed. My delivery slip reads:
Dyed unmarked heating oil: not for use in highway or non-highway, locomotive
or marine engines.