Keep your Ohio CAT Challenger or other diesel engines on the farm or in your business running in top condition with a fifty-five (55) gallon drum of Caterpillar 15W40 Diesel Engine Oil (DEO), Part #3E9712. CAT DEO is recommended for agriculture, earthmoving, commercial, marine and on-highway truck diesel engines, including low-emission diesel engines including CAT engines with ACERT Technology. All heavy-duty diesel engines that recommend API CI-4 PLUS, CH-4 or CG-4 category oil could use this product.