Cars & Vehicles
Oil and Oil Filters
Will It Hurt A Diesel Truck to be topped off with 3 quarts of 10w30 when it calls for 15w40?
In an emergency, no. Change the oil ASAP. If it's an
emergency.... only if you have to do so. It can hurt it. Diesel oil
(15w40) is different from 10w30. There are different additives,
different qualities, and the viscosity is also different.