Heaviside would be a very negative connotation for trucks and ATVs. Most people would think heavy-side or top-heavy, which is the opposite of what you want a truck to be, and not Heaviside the engineer who lent his name to the punniest function in mathematics.
Or they might think heavy-industry or heavy-duty, which would be a good/neutral connotation.
...and heavy has stopped looking like a real word now.