Are SUV's commercial vehicles

Not unless they're used for such a purpose. Even then, they'd need a Gross Vehicle Weight Rating in excess of 10,000 lbs. (or be towing a trailer which brings the combined Gross Combination Weight Rating over 10,000 lbs.) before they'd be considered a CMV. IIRC, the Ford Excursion and Hummer H1 are the only factory SUVs to meet those weight requirements.