Niteo MOTOR MEDIC M7112 Diesel Fuel Sulfur Substitute - 12 oz. MOTOR MEDIC is a local family owned company based out of Charlotte, NC. For more than 75 years, LIQUID WRENCH products, developed by the people who use them, has earned the trust of hard-working tradesment and the active DIYer through consistent, superior performance and a commitment to innovation.MOTOR MEDIC